U.S. patent application number 11/550261 was filed with the patent office on 2007-07-05 for methods and apparatus to maintain audience privacy while determining viewing of video-on-demand programs.
Invention is credited to Robert A. Luff, Arun Ramaswamy.
Application Number | 20070157262 11/550261 |
Document ID | / |
Family ID | 35242340 |
Filed Date | 2007-07-05 |
United States Patent
Application |
20070157262 |
Kind Code |
A1 |
Ramaswamy; Arun ; et
al. |
July 5, 2007 |
METHODS AND APPARATUS TO MAINTAIN AUDIENCE PRIVACY WHILE
DETERMINING VIEWING OF VIDEO-ON-DEMAND PROGRAMS
Abstract
Methods and apparatus to maintain audience privacy while
determining viewing of video-on-demand programs are disclosed. An
example method for monitoring a displayed VOD program disclosed
herein comprises determining a first set of metering information
based on a first set of data collected at a subscriber site,
determining a second set of metering information based on a second
set of data reported by at least one of a VOD server and a
head-end, determining a third set of data based on the second set
of data, and combining the first and third sets of metering
information to credit the displayed VOD program.
Inventors: |
Ramaswamy; Arun; (Tampa,
FL) ; Luff; Robert A.; (New York, NY) |
Correspondence
Address: |
HANLEY, FLIGHT & ZIMMERMAN, LLC
150 S. WACKER DRIVE
SUITE 2100
CHICAGO
IL
60606
US
|
Family ID: |
35242340 |
Appl. No.: |
11/550261 |
Filed: |
October 17, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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PCT/US05/13765 |
Apr 22, 2005 |
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11550261 |
Oct 17, 2006 |
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60564777 |
Apr 23, 2004 |
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Current U.S.
Class: |
725/87 ;
348/E7.069; 725/46; 725/86 |
Current CPC
Class: |
H04N 21/254 20130101;
H04H 60/45 20130101; H04H 20/14 20130101; H04H 2201/90 20130101;
H04N 21/6582 20130101; H04N 21/8352 20130101; H04H 60/64 20130101;
H04H 60/372 20130101; H04N 21/442 20130101; H04N 21/44222 20130101;
H04H 60/58 20130101; H04N 21/25866 20130101; H04N 7/173 20130101;
H04N 21/47202 20130101; H04H 60/59 20130101; H04H 60/43 20130101;
H04H 60/40 20130101 |
Class at
Publication: |
725/087 ;
725/086; 725/046 |
International
Class: |
H04N 7/173 20060101
H04N007/173; G06F 13/00 20060101 G06F013/00; H04N 5/445 20060101
H04N005/445; G06F 3/00 20060101 G06F003/00 |
Claims
1. A method to monitor presentation of video-on-demand (VOD)
content comprising: determining subscriber metering data reflecting
presentation of VOD media content to a subscriber site; determining
server metering data corresponding to a VOD server configured to
provide the VOD content to the subscriber site; manipulating at
least a portion of the subscriber metering data and at least a
portion of the server metering data to preserve anonymity of a
subscriber associated with the subscriber site; and merging the
subscriber metering data and the server metering data based on the
at least a portion of the subscriber metering data and the at least
a portion of the server metering data.
2. (canceled)
3. A method as defined in claim 1 wherein determining the
subscriber metering data comprises generating a viewing record.
4. A method as defined in claim 3 wherein the viewing record
comprises at least one of a VOD indicator, a home unit identifier,
a set-top box identifier, channel tuning data or VOD selection
data.
5. A method as defined in claim 3 wherein the viewing record
comprises a set of entries corresponding to media content presented
at the predetermined time intervals.
6.-8. (canceled)
9. A method as defined in claim 1 wherein the subscriber metering
data comprises at least one of content identification codes,
content signatures, or audience demographics.
10. A method as defined in claim 1 wherein the at least a portion
of the subscriber metering data comprises subscriber identification
information.
11. A method as defined in claim 10 wherein the subscriber
identification information comprises a set-top box identifier or a
home unit identifier.
12.-13. (canceled)
14. A method as defined in claim 1 wherein the server metering data
comprises at least one of VOD content information or subscriber
identification information.
15. A method as defined in claim 14 wherein the VOD content
information comprises a VOD content title.
16. A method as defined in claim 14 wherein the subscriber
identification information comprises at least one of a set-top box
identifier, a subscriber name or a subscriber address.
17.-21. (canceled)
22. A method as defined in claim 1 wherein manipulating the at
least the portion of the subscriber metering data and the at least
the portion of the server metering data comprises encrypting the at
least the portion of the subscriber metering data or the at least
the portion of the server metering data.
23. A method as defined in claim 22 wherein the at least the
portion of the subscriber metering data or the at least the portion
of the server metering data comprises subscriber identification
information.
24. A method as defined in claim 23 wherein encrypting the at least
the portion of the subscriber metering data or the at least the
portion of the server metering data comprises processing the
subscriber identification information with a hash function.
25.-26. (canceled)
27. A method as defined in claim 1 wherein manipulating the at
least the portion of the subscriber metering data and the at least
the portion of the server metering data comprises replacing
subscriber identification information with a hash identifier.
28. A method as defined in claim 1 wherein merging the subscriber
metering data and the server metering data comprises adding at
least a portion of the server metering data corresponding to the
subscriber site to the subscriber metering data.
29. A method as defined in claim 28 wherein merging the subscriber
metering data and the server metering data comprises using the at
least the portion of the subscriber metering data to identify a
relevant portion of the server metering data while preserving the
anonymity of the subscriber.
30. A method as defined in claim 1 wherein merging the subscriber
metering data and the server metering data comprises augmenting the
subscriber metering data with a selected portion of the server
metering data.
31. A method as defined in claim 30 wherein augmenting the
subscriber metering data with the selected portion of the server
metering data comprises replacing a VOD indicator with the selected
portion of the server metering data.
32. A method as defined in claim 31 wherein replacing the VOD
indicator with the selected portion of the server metering data
comprises comparing a first timestamp corresponding with the VOD
indicator with a second timestamp associated with the selected
portion of the server metering data.
33.-40. (canceled)
41. A method to exchange personal data, the method comprising:
providing a first set of personal data corresponding to a first set
of individuals associated with a first entity to a second entity,
wherein identities of the first set of individuals are hidden from
the second entity; creating a set of personal data keys
corresponding to a second set of individuals associated with the
second entity; using the set of personal data keys to identify a
portion of the first set of personal data corresponding to a
particular individual in the first set of individuals and in the
second set of individuals; and merging the portion of the first set
of personal data corresponding to the particular individual with a
second set of personal data associated with the second entity
without identifying the particular individual to the first
entity.
42. A method as defined in claim 41 wherein the first set of
personal data comprises an encrypted set of personal identification
information corresponding respectively to the first set of
individuals.
43. A method as defined in claim 41 wherein using the set of
personal data keys to identify the portion of the first set of
personal data corresponding to the particular individual comprises
using a key representative of the particular individual created
from personal identification information known to the second
entity.
44. A method as defined in claim 43 wherein the key substantially
matches encrypted personal identification information included in
the first set of personal data and associated with the particular
individual.
45. A method as defined in claim 41 wherein the second entity is a
neutral party facilitating the exchange of personal data between
the first entity and a third entity, and the second set of
individuals and the second set of personal data originates at the
third entity.
46. A method to share data between a service provider and an
audience measurement company, the method comprising: providing a
data set from the service provider to the audience measurement
company, wherein the data set comprises service usage data and
first identification data collected by the service provider from
subscribers of the service provider, and the first identification
data is encrypted to hide the subscribers' identities from the
audience measurement company; encrypting second identification data
associated with audience members monitored by the audience
measurement company; identifying subscribers of the service
provider who are also audience members monitored by the audience
measurement company by comparing the encrypted second
identification data with the encrypted first identification data in
the data set; and adding portions of the service usage data from
the data set for the identified subscribers to a database of the
audience measurement company, wherein the audience members
monitored by the audience measurement company are not identified to
the service provider and subscribers of the service provider who
are not audience members monitored by the audience measurement
company are not identified to the audience measurement company.
47. A method as defined in claim 46 wherein the service usage data
and first identification data in the data set is for substantially
all of the subscribers of the service provider.
48. A method as defined in claim 46 wherein the audience
measurement company discards all portions of the service usage data
from the data set which correspond to subscribers of the service
provider that are not audience members monitored by the audience
measurement company.
49.-59. (canceled)
Description
RELATED APPLICATIONS
[0001] This patent is a continuation of International Application
Serial Number PCT/US05/013765, entitled "Methods and Apparatus to
Maintain Audience Privacy while Determining Viewing of
Video-on-Demand Programs" and filed on Apr. 22, 2005. This patent
also claims priority from U.S. Provisional Application Ser. No.
60/564,777, entitled "Methods and Apparatus to Maintain Audience
Privacy While Determining Viewing of Video-on-Demand Programs" and
filed on Apr. 23, 2004. International Application Serial Number
PCT/US05/013765 and U.S. Provisional Application Ser. No.
60/564,777 are hereby incorporated by reference in their
entireties.
FIELD OF THE DISCLOSURE
[0002] This disclosure relates generally to audience measurement
and, more particularly, to methods and apparatus to maintain
audience privacy while determining viewing of video-on-demand
programs.
BACKGROUND
[0003] Television ratings and metering information is typically
selected households typically has a data logging and processing
unit commonly referred to as a "home unit." In households having
multiple viewing sites (e.g., multiple television systems), the
data logging and processing functionality may be distributed among
a single home unit and multiple "site units," one site unit for
each viewing site. The home unit (or the combination of the home
unit and the site unit) is often in communication with a variety of
attachments that provide inputs to the home unit or receive outputs
from the home unit. For example, a source identification unit such
as a frequency detector attachment may be in communication with a
television to sense a local oscillator frequency of the television
tuner. In this manner, the frequency detector attachment may be
used to determine the channel to which the television is currently
tuned based on a detected frequency. Additional source
identification devices, such as on-screen readers and
light-emitting-diode (LED) display readers, may be provided, for
example, to determine if the television is operating (i.e., is
turned ON) and/or the channel to which the television is tuned. A
people counter may be located in the viewing space of the
television and in communication with the home unit, thereby
enabling the home unit to detect the identities and/or number of
the persons currently viewing programs displayed on the
television.
[0004] The home unit usually processes the inputs (e.g., channel
tuning information, viewer identities, etc.) from the attachments
to produce viewing records. Viewing records may be generated on a
periodic basis (e.g., at fixed time intervals) or may be generated
in response to one or more predetermined events, such as a full
memory, or a change in an input, such as a change in the identities
of the persons viewing the television, a change in the channel
tuning information (i.e., a channel change), etc. Each viewing
record typically contains channel information, such as a channel
number and/or station identification (ID), and a time (e.g., a date
and time-of-day) at which the channel was displayed. In cases in
which the program content being displayed is associated with a
local audio/video content delivery device, such as a digital video
disk (DVD) player, a digital video recorder (DVR), a video cassette
recorder (VCR), etc., the viewing records may include content
identification (i.e., program identification) information as well
as information relating to the time and manner in which the
associated content was displayed. Viewing records may also contain
additional information, such as the number of viewers present at
the viewing time.
[0005] The home unit typically collects a quantity of viewing
records and periodically (e.g., daily) transmits the collected
viewing records to a central office or data processing facility for
further processing or analysis. The central data processing
facility receives viewing records from home units located in some
or all of the statistically selected households and analyzes the
viewing records to ascertain the viewing behaviors of households in
a geographic area or market of interest, a particular household
and/or a particular group of households selected from all
participating households. Additionally, the central data processing
facility may generate metering statistics and other parameters
indicative of viewing behavior associated with some or all of the
participating households. This data may be extrapolated to reflect
the viewing behaviors of markets and/or regions modeled by the
statistically selected households.
[0006] To generate viewing behavior information from viewing
records, the central office or data processing facility may compare
reference data, such as a list of programs (e.g., a schedule of
television programming or a television guide), to the viewing
records. In this manner, the central office can infer which program
was displayed by cross-referencing the time and channel information
in a viewing record to the program associated with that same time
and channel in the program schedule. Such a cross-referencing
process can be carried out for each of the viewing records received
by the central office, thereby enabling the central office to
reconstruct which programs were displayed by the selected
households and the times at which the programs were displayed. Of
course, the aforementioned cross-referencing process is unnecessary
in systems in which the identity of the program is obtained by the
home unit and contained in the viewing record.
[0007] The rapid development and deployment of a wide variety of
audio/video content delivery and distribution platforms has
dramatically complicated the home unit task of providing viewing
records or information to the central data collection facility. For
instance, while the above-mentioned frequency detector device can
be used to detect channel information at a site where network
television broadcasts are being displayed (because, under normal
operation conditions, the local oscillator frequency corresponds to
a known network channel), such a device typically cannot be used
with digital broadcast systems. In particular, digital broadcast
systems (e.g., satellite-based digital television systems, digital
cable systems, etc.) typically include a digital receiver or
set-top box at each subscriber site. The digital receiver or
set-top box demodulates a multi-program data stream, parses the
multi-program data stream into individual audio and/or video data
packets, and selectively processes those data packets to generate
an audio/video signal for a desired program. The audio and/or video
output signals generated by the set-top box can be directly coupled
to an audio/video input of an output device (e.g., a television, a
video monitor, etc.) As a result, the local oscillator frequency of
the output device tuner, if any, does not necessarily identify the
channel or program currently being displayed.
[0008] To allow generation of meaningful viewing records in cases
wherein, for example, the network channel is not readily
identifiable or may not uniquely correspond to a displayed program,
metering techniques based on the use of ancillary codes and/or
content signatures may be employed. Metering techniques that rely
on ancillary codes often encode and embed identifying information
(e.g., a broadcast/network channel number, a program identification
code, a broadcast time stamp, a source identifier to identify a
network and/or station providing and/or broadcasting the content,
etc.) in the broadcast signal such that the code is not noticed by
the viewer. For example, a well-known technique used in television
broadcasting involves embedding the ancillary codes in the
non-viewable vertical blanking interval of the video signal.
Another example involves embedding the ancillary codes in
non-audible portions of the audio signal accompanying the broadcast
program. This latter technique is especially advantageous because
the ancillary code may be reproduced by, for example, the
television speaker and non-intrusively monitored by an external
sensor, such as a microphone.
[0009] In general, signature-based program identification
techniques use one or more characteristics of the currently
displayed (but not yet identified) audio/video content to generate
a substantially unique proxy or signature (e.g., a series of
digital values, a waveform, etc.) for that content. The signature
information for the content being displayed may be compared to a
set of reference signatures corresponding to a known set of
programs. When a substantial match is found, the currently
displayed program content can be identified with a relatively high
probability.
[0010] While the known apparatus and techniques described above are
well-suited for generating viewing records associated with live
viewing of broadcast television programming, they may not be
directly applicable to the generation of viewing records associated
with video-on-demand (VOD) programs. In a VOD system, a subscriber
may select among a potentially large collection of programming
content to be transmitted to the specific subscriber's home for
immediate viewing or for viewing at a later time. Thus, existing
metering techniques based on cross-referencing a predetermined
broadcast programming guide or television listing are not
applicable because the content to be transmitted to the
subscriber's home is not known prior to when the subscriber makes
the selection. Thus, existing techniques would require a
computationally expensive brute-force search over all possible
reference broadcast and VOD content to determine the specific VOD
content being consumed at the subscriber's home (because existing
metering techniques typically do not distinguish whether the source
of the consumed programming content is a broadcast or a VOD
source). Moreover, the existing metering techniques may not be able
to distinguish between content that may be provided by both a
broadcast provider and a VOD provider and, as such, may incorrectly
credit the source of the consumed programming content.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a block diagram of an example local metering
system coupled to an example home entertainment system.
[0012] FIG. 2 is a block diagram of an example broadcast system and
an example monitoring system.
[0013] FIG. 3 is a block diagram of an example monitoring system
for video-on-demand (VOD) programming that may employ metered data
from a VOD server and/or a statistically selected home.
[0014] FIG. 4 illustrates an example viewing record generated by
the local metering system of FIG. 1.
[0015] FIG. 5 is a flowchart of an example process to monitor VOD
programming that may employ metered data from a VOD server and a
statistically selected home.
[0016] FIG. 6 is a block diagram of an example metering record
hashing unit which may be used to implement at least portions of
the example process of FIG. 5.
[0017] FIG. 7 illustrates an example operation of the example
metering record hashing unit of FIG. 6.
[0018] FIG. 8 is a block diagram of an example hashed metering
database processor which may be used to implement at least portions
of the example process of FIG. 5.
[0019] FIG. 9 is a flowchart representative of example machine
readable instructions which may be executed by a machine to
implement the example metering record hashing unit of FIG. 6.
[0020] FIGS. 10A-10B are a flowchart representative of example
machine readable instructions which may be executed by a machine to
implement the example hashed metering database processor of FIG.
8.
[0021] FIG. 11 is a block diagram of an example computer that may
be used to implement the example programs represented by the
flowcharts of FIGS. 9 and 10A-10B.
DETAILED DESCRIPTION
[0022] A block diagram of an example local metering system 100
capable of providing viewing and metering information for
video-on-demand program content via an example home entertainment
system 102 is illustrated in FIG. 1. The example home entertainment
system 102 includes a broadcast source 104, a set-top box (STB)
108, a signal splitter 116 and a television 120. The example local
metering system 100 includes a home unit 124. The components of the
home entertainment system 102 and the local metering system 100 may
be connected in any well-known manner including that shown in FIG.
1. For example, in a statistically selected household having one or
more home entertainment systems 102, the home unit 124 may be
implemented as a single home unit and one or more site units. In
such a configuration, the single home unit performs the functions
of storing data and forwarding the stored data to a central
facility (such as the central facility 211 of FIG. 2 discussed
below) for subsequent processing. Each site unit is coupled to a
corresponding home entertainment system 102 and performs the
functions of collecting viewing/metering data, processing such data
(possibly in real-time) and sending the processed data to the
single home unit for that home. The home unit receives and stores
the data collected by the site units and subsequently forwards that
collected data to the central facility.
[0023] The broadcast source 104 may be any broadcast media source,
such as a cable television service provider, a satellite television
service provider, a radio frequency (RF) television service
provider, an internet streaming video/audio provider, etc. The
broadcast source 104 may provide analog and/or digital television
signals to the home entertainment system 102, for example, over a
coaxial cable or via a wireless connection.
[0024] The STB 108 may be any set-top box, such as a cable
television converter, a direct broadcast satellite (DBS) decoder, a
video cassette recorder (VCR), etc. The set-top box 108 receives a
plurality of broadcast channels from the broadcast source 104.
Typically, the STB 108 selects one of the plurality of broadcast
channels based on a user input, and outputs one or more signals
received via the selected broadcast channel. In the case of an
analog signal, the STB 108 tunes to a particular channel to obtain
programming delivered on that channel. For a digital signal, the
STB 108 may tune to a channel and decode certain packets of data to
obtain programming delivered on a selected channel. For example,
the STB 108 may tune to a major channel and then extract a program
carried on a minor channel within the major channel via the
decoding process mentioned above. For some home entertainment
systems 102, for example, those in which the broadcast source 104
is a standard RF analog television service provider or a basic
analog cable television service provider, the STB 108 may not be
present as its function is performed by a tuner in the television
120.
[0025] An output from the STB 108 is fed to a signal splitter 116,
such as a single analog y-splitter in the case of an RF coaxial
connection between the STB 108 and the television 120 or an
audio/video splitter in the case of a direct audio/video connection
between the STB 108 and the television 120. (For configurations in
which the STB 108 is not present, the broadcast source 104 may be
coupled directly to the signal splitter 116). In the example home
entertainment system 102, the signal splitter produces two signals
indicative of the output from the STB 108. Of course, a person of
ordinary skill in the art will readily appreciate that any number
of signals may be produced by the signal splitter 116.
[0026] The STB 108 may also be coupled to a back-channel connection
128 to provide a return communication path to the broadcast signal
provider corresponding to the broadcast source 104. The STB 108 may
use the back-channel connection 128 to send billing and/or status
information to the broadcast provider. The back-channel connection
128 may also allow a subscriber to use the STB 108 to request/order
content for viewing on the television 120 (e.g., pay-per-view
movies, video-on-demand programming, etc.), purchase goods and/or
services, modify the subscription package associated with the STB
108, etc.
[0027] In the illustrated example, one of the two signals from the
signal splitter 116 is fed to the television 120 and the other
signal is delivered to the home unit 124. The television 120 may be
any type of television or television display device. For example,
the television 120 may be a television and/or display device that
supports the National Television Standards Committee (NTSC)
standard, the Phase Alternating Line (PAL) standard, the Systeme
Electronique pour Couleur avec Memoire (SECAM) standard, a standard
developed by the Advanced Television Systems Committee (ATSC), such
as high definition television (HDTV), a standard developed by the
Digital Video Broadcasting (DVB) Project, or may be a multimedia
computer system, etc.
[0028] The second of the two signals from the signal splitter 116
(i.e., the signal carried by connection 136 in FIG. 1) is coupled
to an input of the home unit 124. The home unit 124 is a data
logging and processing unit that may be used to generate viewing
records and other viewing information useful for determining
viewing and other metering information. The home unit 124 typically
collects a set of viewing records and transmits the collected
viewing records over a connection 140 to a central office or data
processing facility (not shown) for further processing or analysis.
The connection 140 may be a telephone line, a return cable
television connection, an RF or satellite connection, an internet
connection or the like.
[0029] The home unit 124 may be configured to determine identifying
information based on the signal corresponding to the program
content being output by the STB 108. For example, the home unit 124
may be configured to decode an embedded ancillary code in the
signal received via connection 136 that corresponds to the program
currently being delivered by the STB 108 for display on the
television 120. Alternatively or additionally, the home unit 124
may be configured to generate a program signature based on the
signal received via connection 136 that corresponds to the program
currently being delivered by the STB 108 for display on the
television 120. The home unit may then add this program identifying
information to the viewing records corresponding to the currently
displayed program.
[0030] To facilitate the determination of programidentifying
information and the generation of viewing records for the currently
displayed program content, the home unit 124 may also be provided
with one or more sensors 144. For example, one of the sensors 144
may be a microphone placed in the proximity of the television 120
to receive audio signals corresponding to the program being
displayed. The home unit 124 may then process the audio signals
received from the microphone 144 to decode any embedded ancillary
code(s) and/or generate one or more audio signatures corresponding
to a program being displayed. Another of the sensors 144 may be an
on-screen display detector for capturing images displayed on the
television 120 and processing regions of interest in the displayed
image. The regions of interest may correspond, for example, to a
broadcast channel associated with the currently displayed program,
a broadcast time associated with the currently displayed program, a
viewing time associated with the currently displayed program, etc.
Example on-screen display detectors are disclosed by Nelson, et al.
in U.S. Provisional Patent Application Ser. No. 60/523,444 filed on
Nov. 19, 2003, and International Patent Application Serial No.
PCT/US04/12272 filed on Apr. 19, 2004, both of which are hereby
incorporated by reference. Yet another of the sensors 144 could be
a frequency detector to determine, for example, the channel to
which the television 120 is tuned. One having ordinary skill in the
art will recognize that there are a variety of sensors 144 that may
be coupled with the home unit 124 to facilitate generation of
viewing records containing sufficient information for the central
office to determine a set of desired ratings and/or metering
results.
[0031] The example home entertainment system 102 also includes a
remote control device 160 to transmit control information that may
be received by any or all of the STB 108, the television 120 and
the home unit 124. One having ordinary skill in the art will
recognize that the remote control device 160 may transmit this
information using a variety of techniques, including, but not
limited to, infrared (IR) transmission, radio frequency
transmission, wired/cabled connection, and the like.
[0032] The example local metering system 100 also includes a people
meter 164 to capture information about the audience. The example
people meter 164 may have a set of input keys, each assigned to
represent a single viewer, and may prompt the audience members to
indicate that they are present in the viewing audience by pressing
the appropriate input key. The people meter 164 may also receive
information from the home unit 124 to determine a time at which to
prompt the audience members. Moreover, the home unit 124 may
receive information from the people meter 164 to modify an
operation of the home unit 124 (such as causing the home unit to
generate one or more viewing records based on a change in the
viewing audience). As will be appreciated by one having ordinary
skill in the art, the people meter 164 may receive and/or transmit
information using a variety of techniques, including, but not
limited to, infrared (IR) transmission, radio frequency
transmission, wired/cabled connection, and the like. As will also
be appreciated by one having ordinary skill in the art, the people
meter 164 may be implemented by a combination of the remote control
device 160 and one or more of the STB 108 and/or the home unit 124.
In such an implementation, the STB 108 and/or the home unit 124 may
be configured to display prompting information and/or other
appropriate people meter content directly on the television 120.
Correspondingly, the remote control device 160 may be configured to
accept inputs from the viewing audience and transmit these user
inputs to the appropriate device responsible for generating the
people meter display on the television 120.
[0033] FIG. 2 illustrates an example monitoring system 200 to
monitor viewing of program content provided by an example broadcast
system 201. The example broadcast system 201 of FIG. 2 includes a
broadcast station 202 that receives audio/video content from a
plurality of content providers 204 and 206. The audio/video content
providers 204 and 206 may provide audio and/or video programs or
information, such as television programs, advertisements, audio
(e.g., radio) programs, still image information (e.g., web pages),
etc., in known manners to the broadcast station 202.
[0034] The example monitoring system 200 of FIG. 2 includes one or
more reference sites 208, a plurality of local metering systems 209
(for example, a set of systems similar or identical to the local
metering system 100 of FIG. 1) located at a plurality of home sites
210 (which may be statistically selected to represent a larger
population) and a central facility 211 to compile and process data
collected by the local metering systems 209. For ease of reference,
only one home site 210, one reference site 208 and one central
facility 211 is shown in FIG. 2. However, persons of ordinary skill
in the art will appreciate that any number of home sites 210,
reference sites 208 and/or central data collection and processing
facilities 211 may be employed.
[0035] The broadcast station 202 transmits one or more signals
containing digital and/or analog audio/video content information.
These signals are received by at least one reference site 208 and
at least one statistically selected home site 210 via communication
paths or links 212 and 214, respectively. The communication paths
or links 212 and 214 may include any combination of hardwired or
wireless links, such as satellite links, wireless land-based links,
cable links, etc. The signals conveyed via the links 212 and 214
may contain multi-program analog signals and/or digital data
streams which are commonly employed within existing broadcast
systems.
[0036] In the example monitoring system 200, the reference site 208
includes a plurality of receivers (e.g., set-top boxes or the like)
216, 218 and 220 that simultaneously demodulate, demultiplex and/or
decode audio, video and/or other information received from the
broadcast station 202. In the illustrated example, each of the
receivers 216, 218 and 220 provides audio and/or video information
associated with a different program that is currently being
broadcast to a reference site processor 222. In other words, the
receiver 216 may provide audio and/or video information associated
with a program A while the receivers 218 and 220 provide audio
and/or video information associated with respective programs B and
C. In addition, the reference site processor 222 is configured to
control each of the receivers 216, 218 and 220 and/or has
information indicating a program to which each of the receivers
216, 218 and 220 is tuned at any given time.
[0037] The reference site processor 222 may determine the original
broadcast date/time stamps, decode reference ancillary code
information and/or generate reference signature information for a
plurality of simultaneously broadcast audio/video content. The
reference site processor 222 sends the original broadcast time
stamps and the reference code and/or signature information to a
central facility processor 224 which stores the original broadcast
time stamps and the reference code and/or signature information in
a database 226.
[0038] The home site 210 could be, for example, a statistically
selected home containing a television, a radio, a computer, etc.
The home site 210 includes an output device 228 (e.g., a video
display, speaker, etc., such as the television 120 of FIG. 1). The
home site 210 also includes a receiver 230, such as the STB 108 of
FIG. 1, which may be similar or identical to the receivers 216, 218
and 220. Such receivers are well-known and, thus, are not described
in greater detail herein. The receiver 230 provides audio and/or
video signals 232 to the output device 228 that are used to present
the program currently selected for consumption.
[0039] To monitor the use of the receiver 230, the home site 210 is
provided with a local metering system 209, such as the local
metering system 100 of FIG. 1. The local metering system 209 may
include, for example, a home unit such as the home unit 124. The
receiver 230 provides an audio and/or a video signal containing
audio and/or video information associated with the currently
displayed program to the local metering system 209 via a connection
234. The local metering system 209 uses the signal received via the
connection 234 to decode ancillary code information and/or generate
signature information corresponding to the program currently being
displayed on the output device 228. The local metering system 209
stores and periodically conveys this code and/or signature
information to the central facility processor 224, for example, in
the form of a viewing record or set of records.
[0040] The central facility processor 224, in addition to being
able to perform other processing tasks, is configured to compare
code and/or signature information generated at the home site 210 to
the reference code and/or signature information stored in the
database 226 to identify the channels and/or programs that were
displayed at the home site 210. To facilitate the comparison of
code and/or signature information received from the reference site
208 to the code and/or signature information received from the home
site 210, the reference site processor 222 and the local metering
system 209 may generate time stamp information and associate such
time stamp information with the code and/or signature information
collected at the corresponding time. In this manner, the central
facility processor 224 can attempt to align the code and/or
signature information received from the reference sites 208 with
the code and/or signature information collected at the
corresponding times via the home site 210 to thereby reduce the
number of comparisons required to identify a match.
[0041] FIG. 3 illustrates an example monitoring system for
video-on-demand (VOD) programming that may employ metered data from
a VOD server and/or a statistically selected home. In the example
environment of use of FIG. 3, the VOD system includes a VOD server
304, a distribution network 308 and multiple subscriber STBs 312,
316. The VOD server 304 may be implemented as a single server or a
collection of servers located in a central location or multiple,
distributed geographical locations. The VOD server 304 stores the
VOD content to be transmitted to the subscriber STBs 312, 316. The
distribution network 308 may be any distribution network that is
able to transmit VOD content to a subscriber location (e.g., an RF
television broadcaster, a cable television service provider, a
satellite service provider, etc.). For example, the distribution
network 308 may be implemented by the broadcast station 202 and the
communication paths 212 and 214 of FIG. 2. The subscriber STBs 312,
316 may be any set-top box, such as the STB 108 of FIG. 1.
[0042] The example monitoring system of FIG. 3 includes a metering
home interface 320, such as the local metering system 100 of FIG.
1, coupled to the STB 316. The metering home interface 320 may be
used to collect viewing data (e.g., TV ON/OFF data, tuning data,
content codes, content signatures, etc.), audience demographics
(e.g., via the people meter 164), etc. The example monitoring
system also includes a metering server interface 324 to collect
data from the VOD server 304. The data may be stored in any
appropriate format, for example, an XML format or equivalent, and
may include VOD content information, such as the VOD content title,
the associated metadata for the VOD content and other subscriber
information, such as an STB identifier (ID) for a given
subscriber's STB. The metered server data may correspond to all VOD
service subscribers, instead of being limited to only those
subscribers included in a statistical sampling of selected
households.
[0043] The example monitoring system of FIG. 3 also includes a
central facility 328, such as the central facility 211 of FIG. 2.
The central facility 328 may receive information from the metering
server interface 324 and/or the metering home interface 320. The
central facility 328 may combine the information received from both
the metering server interface 324 and/or the metering home
interface 320 to credit VOD programming and to generate
corresponding usage and demographic reports. For example, the
central facility 328 may use the STB ID for the STB 316 to match
the data from metering home interface 320 to the corresponding data
received from the metering server interface 324.
[0044] To better understand the benefits of collecting metering
data from a VOD metering server interface (e.g., the metering
server interface 324 of FIG. 3), an example viewing record 400
generated by a local metering system, (e.g., the local metering
system 100 of FIG. 1 or the metering home interface 320 of FIG. 3)
is shown in FIG. 4. The viewing record is typically generated by a
home unit, such as the home unit 124 of FIG. 1, and reported to a
central facility, such as the central facility 328 of FIG. 3. The
home unit 124 may send the stored viewing records to the central
facility 328, for example, at periodic intervals (e.g., once a
day), continuously, or at a-periodic intervals (e.g., whenever a
predetermined event occurs). One having ordinary skill in the art
will appreciate that a variety of viewing records substantially
equivalent to the viewing record 400 may be generated by the home
unit 124. Such viewing records may include metering information in
addition to and/or different from the example 400 of FIG. 4, yet
may still be used by the methods and/or apparatus described
herein.
[0045] Turning to FIG. 4, the example viewing record 400 includes a
home unit ID 404 to identify the home unit 124 that
generated/reported the viewing record. The viewing record 400 may
also include a STB ID 408 corresponding to the STB, such as the STB
316, that selected and/or presented the displayed broadcast or VOD
programming content. The home unit ID 404 and/or the STB ID 408 may
be used by the central facility 328 to cross-reference the reported
viewing record 400 with the corresponding VOD server data provided
by the metering server interface 324.
[0046] The example viewing record also includes sets of channel
data information 412, 414, 416 corresponding to channels of the STB
316 selected by the user/subscriber. In the instant example, the
home unit 124 is configured to poll the STB 316 at periodic
intervals (e.g., once every 2.7 sec.) to determine the channel
number selected by the STB 316. Additionally, the home unit 124 may
be configured with a mapping table, for example, to map sets of
channels into larger supersets of channels having similar content.
For example, a set of broadcast channels used to carry pay-per-view
programming may be grouped into a single superset representing all
receivable pay-per-view content. Similarly, a set of broadcast
channels used to carry VOD programming may be grouped and
represented by a single superset used to indicate that VOD content
was selected/output by the STB 316. As a result, the channel data
412, 414 that the home unit 124 includes in the example viewing
record 400 may comprise the channel number selected by the STB 316
and the timestamp at which the measurement was taken. Additionally
or alternatively, the home unit 124 may include VOD data 416 in the
example viewing record 400, with the VOD data 416 including an
entry indicating that any member of the superset of VOD channels
was selected (represented by "VOD" in FIG. 4) and the timestamp at
which the measurement was taken. Thus, as one having ordinary skill
in the art will recognize, the example viewing record 400 may be
used to indicate that at least one of a superset of VOD channels
was selected by the STB 316. However, the actual VOD channel
selected and/or the actual VOD content selected/output by the STB
316 cannot be readily determined solely from the data included in
the example viewing record 400.
[0047] To determine the actual selected/displayed VOD content
corresponding to a reported viewing record, such as the example
viewing record 400 of FIG. 4, an example process 500 to maintain
subscriber privacy while combining metering data from a VOD server
with metering data reported from one or more statistically selected
homes is illustrated in the flowchart of FIG. 5. Examples of the
types of metering data which may be provided by a VOD server are
described in U.S. Patent Application Serial No. PCT/US05/05271,
which is hereby incorporated by reference in its entirety. Using
FIG. 3 as a reference, to perform the example process 500, a VOD
metering server interface, such as the metering server interface
324, is configured to send a database of metering data for all
households served by a VOD server, such as the VOD server 304, to a
central facility, such as the central facility 328. Additionally or
alternatively, the metering server interface 324 may be configured
to send the database (or portions thereof) to a neutral third party
site. In either case, such a VOD server metering database may be
constructed to maintain the privacy of all VOD service subscribers
by, for example, encrypting any subscriber identification
information contained in the database. For example, a cryptographic
hash function may be used to convert each subscriber's name,
address and STB ID to a unique hash identifier for a given
subscriber.
[0048] A cryptographic hash function takes as input a variable-size
bit string/message (not exceeding a maximum size for the particular
hash function) and outputs a fixed-size output bit string, also
known as a message digest. As defined in the art, a good hash
function is one in which the transformation is easy to compute,
one-way (i.e., given the output bit string it is not possible, or
at least not practical, to construct the original input string) and
collision-free (i.e., given any two input bit strings it is not
possible, or at least not probable, that both bit strings will
produce the same output bit string). By replacing the original
subscriber identification information with a hash identifier, it is
possible to uniquely associate a subscriber's VOD metering data
with a particular subscriber without revealing the identity of the
subscriber.
[0049] A user of a VOD server hashed database (i.e., a database
containing subscriber hash identifiers in lieu of cleartext
subscriber identification information) may reconstruct the unique
hash identifier for a subscriber for which the user already knows
the particular subscriber's personal information (e.g., as in the
case of a known, statistically-selected metering household).
However, due to the one-way and collision-free properties of the
hash function, the database user is not able to determine or
decrypt the personal information corresponding to the hash
identifier of a subscriber who is unknown to the user. Thus, the
privacy of subscribers not belonging to, for example, the
statistically selected metering households is maintained. One
having ordinary skill in the art will appreciate that any
well-known cryptographic hash function may be employed, such as the
MD-2, MD-4 and MD-5 message digest algorithms available as Internet
RFCs 1319, 1320 and 1321, respectively, the Secure Hash Standard
(SHS) family of algorithms defined by the National Institute of
Standards and Technology (NIST), etc.
[0050] After receiving the VOD-server hashed database, the central
facility 328 stores the data in this database and then
cross-references such data based on, for example, a unique hash
identifier derived from home site personal information provided in
and/or associated with the example viewing record 400. The central
facility 328 may then augment the VOD data reported in the viewing
record 400 with the corresponding, specific VOD content information
included in the VOD server metering database provided by the
metering server interface 324.
[0051] Turning to FIG. 5, the example process 500 begins at block
504 at which the metering server interface 324 sends the hashed
metering database for all households served by the VOD server 304
to the central facility 328 (and/or a neutral third-party site
accessible by the central facility 328). The metering server
interface 324 may be configured to send this hashed database at
predetermined times, for example, at periodic (e.g., daily)
intervals. Alternatively, the metering server interface 324 may
send the database upon the occurrence of one or more predetermined
events (e.g., in response to a request from the central facility
328, when a predetermined amount of data is collected, etc.). At
some time or times after processing at block 504 completes, control
proceeds to block 508 at which the central facility 328 gets one or
more viewing records (such as the example viewing record 400 of
FIG. 4) received from at least one metering home interface 320
(e.g., records generated and reported by a home unit, such as home
unit 124, included in the metering home interface 320). Then at
block 512, the central facility 328 determines whether VOD data
(e.g., VOD data 416) is included in the reported viewing record
400. If VOD data is not present (block 512), control proceeds to
block 532.
[0052] If VOD data 416 is present in the received viewing record
400 (block 512), control proceeds to block 514 at which the central
facility 328 generates a unique hash identifier (hash ID) for the
home site corresponding to the reported viewing record 400 using
the same hash function employed by the VOD server 304 and/or the
metering server interface 324 to create the VOD server hashed
database. The central facility 328 may generate the unique hash ID
based on personal information included in the viewing record 400
(e.g., a STB ID 408), personal information stored in another local
database and referenced by data included in the viewing record 400
(e.g., name, address and STB ID information stored in a local
database and indexed by the home unit ID 404), etc. Control then
proceeds to block 516 at which the central facility 328 uses the
hash ID generated at block 514 to cross-reference the VOD server
hashed database received at block 504. If a match is found (block
520), control proceeds to block 524 at which the central facility
328 selects the corresponding entry or entries in the VOD server
hashed database and combines the selected VOD server metering data
with the reported viewing record 400 being processed (e.g., by
replacing the generic VOD data 416 with specific VOD server
metering data included in the VOD server hashed database). If,
however, a cross-referencing match is not found (block 520),
control proceeds to block 528 at which the central facility 328
indicates that VOD server metering information is not available for
the viewing record 400 being processed. Control then proceeds from
either block 524 or block 528 to block 532.
[0053] At block 532, the central facility 328 determines whether
the viewing record 400 is the last viewing record to be processed.
If the viewing record 400 is not the last record to be processed
(block 532), control returns to block 508 and blocks subsequent
thereto at which the central facility 328 processes the next
received viewing record. Conversely, if the viewing record 400 is
the last record to be processed (block 532), control proceeds to
block 536 at which the central facility 328 generates
ratings/metering reports for home sites that reported viewing
records 400 corresponding to the presentation of VOD programming
content. The example process 500 then ends.
[0054] One having ordinary skill in the art will appreciate that
the processing represented by blocks 508 through 536 may be
executed, for example, on an event-driven basis corresponding to
the receipt of one or more viewing records from one or more
households. Such processing may also be iterated multiple times,
for example, one iteration for each received viewing record, one
iteration for each instance of reported VOD data in a received
viewing record, etc.
[0055] A block diagram of an example metering record hashing unit
600 that may be used to create the VOD server hashed database
discussed above is shown in FIG. 6. In the instant example, the
metering record hashing unit 600 operates on a cleartext (i.e.,
non-encrypted) version of a VOD server metering database (e.g., VOD
server cleartext database 604) to produce a VOD server hashed
database 608 in which personal subscriber data is replaced with
unique subscriber hash IDs. However, the VOD metering data remains
in a cleartext format (i.e., non-encrypted). Thus, processing of
the VOD server hashed database 608 is greatly simplified because
decrypting of the VOD server data is not required. Subscriber
privacy is maintained by employing a comparison of subscriber hash
IDs to retrieve VOD server data. Thus, a user of the VOD server
hashed database 608 is required to already possess the requisite
personal information corresponding to a subscriber in order to
generate the subscriber's unique hash ID and access the
corresponding VOD server data. One having ordinary skill in the art
will appreciate that the contents of the cleartext database 604 and
hashed database 608 may exist as individual fields in a single
database, as data in multiple databases, etc.
[0056] The metering record hashing unit 600 includes a record
retriever 612 to retrieve VOD metering records from the VOD server
cleartext database 604. The record retriever 612 provides the
retrieved metering record to at least one of a subscriber name
retriever 616, a subscriber address retriever 620 and a subscriber
STB ID retriever 624 to retrieve the subscriber name, address
and/or STB ID, respectively, stored in the retrieved metering
record. The subscriber name retriever 616, subscriber address
retriever 620 and subscriber STB ID retriever 624 then provide the
retrieved subscriber name, address and STB ID, respectively, to a
corresponding name formatter 628, address formatter 632 and STB ID
formatter 636. In the instant example, the name formatter 628
formats the subscriber name into a bit string based on an ASCII
representation of the letters in the subscriber name. Similarly,
the address formatter 632 formats the subscriber address into a bit
string based on an ASCII representation of the numbers and/or
letters in the subscriber address. The STB ID formatter 636 may
format the STB ID into a bit string based on a binary
representation of the MAC (medium access control) address of the
STB. One having ordinary skill in the art will appreciate that many
types of data representations may be employed by the name formatter
628, address formatter 632 and STB ID formatter 636. However, it is
necessary that the same formatting techniques be used by the
metering record hashing unit 600 and the hashed metering database
processor 800 (discussed below) so that the same hashed ID is
generated for a particular subscriber.
[0057] A concatenator 640 processes the subscriber name, address
and STB ID formatted by the name formatter 628, address formatter
632 and STB ID formatter 636, respectively, to create a single
value (e.g., bit string) corresponding to the retrieved VOD
metering record. For example, the concatenator 640 may append the
formatted name, address and STB ID together to form a single,
concatenated bit stream corresponding to a particular user. One
having ordinary skill in the art will recognize that concatenated
bit streams for different subscribers may have different lengths.
Additionally, one having ordinary skill in the art will appreciate
that other techniques may be used by the concatenator 640 to
combine the inputs into a single output value. For example, the
concatenator 640 could pad or truncate the formatted name, address
and STB ID inputs to form fixed-length input bit streams and then
exclusive-OR the input bit streams together to form the output bit
stream. Alternatively, the output of the concatenator 640 may be
padded or truncated to create a bit stream of a desired fixed
length.
[0058] The concatenator 640 provides the concatenated bit stream to
a hash generator 644. The hash generator 644 executes a
cryptographic hashing function on the concatenated bit stream to
generate a unique hash ID corresponding to the subscriber
information in the retrieved VOD metering record. The hash
generator 644 then stores the hash ID in association with the
corresponding cleartext VOD metering data (but without any
subscriber identification information) in the VOD server hashed
database 608. As discussed above, the hash generator 644 may employ
a hash function that is easy to compute, one-way (i.e., given the
output bit string it is not possible, or at least not practical, to
construct the original input string) and collision-free (i.e.,
given any two input bit strings it is not possible, or at least not
probable, that both bit strings will produce the same output bits
string). Thus, the output of the hash generator 644 will preferably
be a unique hash ID that may be used in lieu of the original
subscriber identification information but may still allow
association of the stored, cleartext VOD metering data with a
particular (but now anonymous) subscriber.
[0059] One having ordinary skill in the art will appreciate that
any subscriber unique information available to both the VOD
provider and the metering service/facility (e.g., any of the
subscriber name, address, STB ID and/or other personal information
(such as a subscriber telephone number), either alone or in
combination) may be used by the metering record hashing unit 600 to
generate the subscriber hash ID.
[0060] To better illustrate the operation of the example metering
record hashing unit 600, the generation of an example hashed VOD
metering record 704 from an example cleartext VOD metering record
708 is shown in FIG. 7. The cleartext VOD metering record 708 may
correspond, for example, to a record retrieved from the VOD server
cleartext database 604 of FIG. 6. Similarly, the hashed VOD
metering record 704 may correspond to a record stored to the VOD
server hashed database 608. In the example of FIG. 7, the cleartext
VOD metering record 708 includes subscriber identification
information 712 and subscriber VOD metering data 716. The
subscriber identification information 712 may include, for example,
a subscriber name, a subscriber address and a subscriber STB ID.
The VOD metering data 716 may include, for example, data
corresponding to the selection, display and termination of VOD
programming content.
[0061] As discussed above, a metering record hashing unit, such as
the metering record hashing unit 600 of FIG. 6, may transform the
subscriber identification information 712 into a unique subscriber
hash ID 720. To perform this transformation, the metering record
hashing unit 600 of the illustrated example formats the subscriber
identification information 712 into a form suitable for input to a
hash generator, such as the hash generator 644. For example, the
metering record hashing unit 600 may format the subscriber
identification information 712 into formatted bit strings 724 based
on the ASCII representation of the name and address, and the binary
representation of the STB ID (shown in hexadecimal format in FIG.
7). The formatted bit strings 724 may then be concatenated and
applied to the hash generator 644 to generate the unique hash ID
720. The unique hash ID 720 is then associated with the original
cleartext VOD metering data 716 to form the hashed VOD metering
record 704.
[0062] A block diagram of an example hashed metering database
processor 800 that may be used to cross-reference a VOD server
hashed database 804, such as the VOD server hashed database 608 of
FIG. 6, is shown in FIG. 8. The hashed metering database processor
800 includes a home site identifier 808 to determine home site
identification information corresponding to a viewing record (e.g.,
the example viewing record 400 of FIG. 4) stored in a central
facility metering database 812. The home site identifier 808 may
determine identification information such as a viewer name, viewer
address and/or viewer STB ID based on personal information included
in the viewing record 400 (e.g., a STB ID 408), personal
information stored in another local database and referenced by data
included in the viewing record 400 (e.g., name, address and STB ID
information stored in a local database and indexed by the home unit
ID 404), etc.
[0063] In the example of FIG. 8, the home site identifier 808
determines a viewer name, address and STB ID corresponding to a
viewing record 400. The home site identifier 808 provides such
information to the corresponding name formatter 816, address
formatter 820 and STB ID formatter 824. The outputs of the
formatters 816, 820, 824 are input to a concatenator 828 whose
output is used by a hash generator 832 to create a unique hash ID
corresponding to the home site that reported the viewing record 400
being processed. The name formatter 816, address formatter 820, STB
ID formatter 824, concatenator 828 and hash generator 832 are
preferably identical to the name formatter 628, address formatter
632, STB ID formatter 636, concatenator 640 and hash generator 644
of FIG. 6. As such, a detailed description of these structures may
be found above and, in the interest of brevity, these structures
are not discussed further herein. Moreover, the functionality of
the name formatter 816, address formatter 820, STB ID formatter
824, concatenator 828 and hash generator 832 should be
substantially identical to the functionality of the name formatter
628, address formatter 632, STB ID formatter 636, concatenator 640
and hash generator 644 so that the hashed metering database
processor 800 and the metering record hashing unit 600 generate the
same hash ID for the same set of input identification
information.
[0064] Returning to FIG. 8, the hash ID generated by the hash
generator 832 is provided to a record identifier 836. The record
identifier 836 uses the input hash ID to cross-reference the VOD
server hashed database 804 to identify one or more records
corresponding to the generated hash ID. If such a record or records
is/are found, the record identifier 836 may combine the VOD
metering data in the VOD server hashed database 804 with the
corresponding viewing record 400 in the central facility database
812.
[0065] Flowcharts representative of example machine readable
instructions for implementing the metering record hashing unit 600
of FIG. 6 and the hashed metering database processor 800 of FIG. 8
are shown in FIGS. 9 and 10A-10B, respectively. In these examples,
the processes represented by each flowchart may be implemented by a
set of machine readable instructions that may comprise one or more
programs for execution by a processor, such as the processor 1112
shown in the example computer 1100 discussed below in connection
with FIG. 11. The one or more programs may be embodied in software
stored on a tangible medium such as a CD-ROM, a floppy disk, a hard
drive, a DVD, or a memory associated with the processor 1112, but
persons of ordinary skill in the art will readily appreciate that
the entire program and/or portions thereof could alternatively be
executed by a device other than the processor 1112 and/or embodied
in firmware or dedicated hardware in a well-known manner. For
example, any or all of the metering record hashing unit 600, any
portion(s) thereof, the hashed metering database processor 800,
and/or any portion(s) thereof could be implemented by any
combination of software, hardware, and/or firmware. Further,
although the example programs are described with reference to the
flowcharts illustrated in FIGS. 9 and 10A-10B, persons of ordinary
skill in the art will readily appreciate that many other methods of
implementing the example methods and apparatus described herein may
alternatively be used. For example, with reference to the
flowcharts illustrated in FIGS. 9 and 10A-10B, the order of
execution of the blocks may be changed, and/or some of the blocks
described may be changed, eliminated, combined and/or subdivided
into multiple blocks.
[0066] An example program 900 to implement the example metering
record hashing unit 600 of FIG. 6 is shown in FIG. 9. The example
program 900 may be used to create the VOD server hashed database
(or contents thereof) provided as input to the example process 500
of FIG. 5. The program 900 may be executed in response to, for
example, a request from a central facility, such as the central
facility 328 of FIG. 3, to send a VOD server hashed database for
processing. The example program 900 begins at block 902 at which
the metering record hashing unit 600 retrieves a metering record,
such as the cleartext VOD metering record 708 of FIG. 7, from a VOD
server cleartext database, such as the VOD server cleartext
database 604 of FIG. 6. Then, at block 904 the metering record
hashing unit 600 determines the subscriber name corresponding to
the cleartext VOD metering record 708. The metering record hashing
unit 600 formats the subscriber name at block 906 into a form
suitable for input to a cryptographic hashing function, for
example, by transforming the subscriber name into a bit string
based on the ASCII representation of the letters comprising the
name. Control then proceeds to block 908.
[0067] At block 908, the metering record hashing unit 600
determines the subscriber address corresponding to the cleartext
VOD metering record 708. The metering record hashing unit 600
formats the subscriber address at block 910 into a form suitable
for input to a cryptographic hashing function, for example, by
transforming the subscriber address into a bit string based on the
ASCII representation of the numbers and/or letters comprising the
address. Control then proceeds to block 912 at which the metering
record hashing unit 600 determines the subscriber STB ID
corresponding to the cleartext VOD metering record 708. The
metering record hashing unit 600 formats the subscriber STB ID at
block 914 into a form suitable for input to a cryptographic hashing
function, for example, by transforming the subscriber STB ID into a
bit string based on the binary representation of the STB MAC
address. Control then proceeds to block 916.
[0068] At block 916, the metering record hashing unit 600
concatenates the formatted subscriber name, address and STB ID into
a single cleartext bit string that identifies the subscriber
corresponding to the cleartext VOD metering record 708. The
metering record hashing unit 600 inputs this concatenated bit
string into a cryptographic hashing function at block 918 to
generate a unique hash ID corresponding to the particular
subscriber (e.g., the unique hash ID 720 of FIG. 7). As discussed
above, any well-known cryptographic hashing function may be
employed at block 918, such as the MD-2, MD-4 and MD-5 message
digest algorithms available as Internet RFCs 1319, 1320 and 1321,
respectively, the SHS family of algorithms defined by NIST,
etc.
[0069] After generation of the hash ID 720 at block 918, control
proceeds to block 920 at which the metering record hashing unit 600
stores the unique hash ID 720 and the original VOD metering data
(e.g., the original VOD metering data 716) to a hashed VOD metering
record (e.g., the hashed VOD metering record 704) in a hashed
version of the VOD server metering database (e.g., the VOD server
hashed database 608 of FIG. 6). Control then proceeds to block 922
at which the metering record hashing unit 600 determines whether
the cleartext VOD metering record 708 is the last record in the VOD
server cleartext database 604. If the cleartext VOD metering record
708 is not the last record (block 922), control returns to block
902 and blocks subsequent thereto at which the metering record
hashing unit 600 processes the next cleartext VOD metering record
in the VOD server cleartext database 604. Conversely, if the
cleartext VOD metering record 708 is the last record in the VOD
server cleartext database 604 (block 922), then the example program
900 ends.
[0070] Although the above example employs specific examples of
personal information to generate the subscriber hash ID, one having
ordinary skill in the art will appreciate that any combination of
personal information may be used by the metering record hashing
unit 600 to generate the subscriber hash ID.
[0071] An example program 1000 to implement the example hashed
metering database processor 800 of FIG. 8 is shown in FIGS.
10A-10B. The example program 1000 may be used to cross-reference
the VOD server hashed database (or contents thereof) provided as
input to the example process 500 of FIG. 5. The program 1000 may be
executed in response to, for example, receipt of one or more
viewing records, such as the example viewing record 400 of FIG. 4,
by a central facility, such as the central facility 328 of FIG. 3.
The example program 1000 begins at block 1002 of FIG. 10A at which
the hashed metering database processor 800 retrieves the viewing
record 400 from a central facility metering database, such as the
central facility metering database 812 of FIG. 8. Then, at block
1004 the hashed metering database processor 800 determines the
viewer name corresponding to the example viewing record 400. The
hashed metering database processor 800 formats the viewer name at
block 1006 into a form suitable for input to a cryptographic
hashing function, for example, by transforming the subscriber name
into a bit string based on the ASCII representation of the letters
comprising the name. Control then proceeds to block 1008.
[0072] At block 1008, the hashed metering database processor 800
determines the viewer address corresponding to the viewing record
400. The hashed metering database processor 800 formats the viewer
address at block 1010 into a form suitable for input to a
cryptographic hashing function, for example, by transforming the
viewer address into a bit string based on the ASCII representation
of the numbers and/or letters comprising the address. Control then
proceeds to block 1012 at which the hashed metering database
processor 800 determines the viewer STB ID corresponding to the
viewing record 400. The hashed metering database processor 800
formats the viewer STB ID at block 1014 into a form suitable for
input to a cryptographic hashing function, for example, by
transforming the viewer STB ID into a bit string based on the
binary representation of the STB MAC address. As discussed above,
the hashed metering database processor 800 may determine the viewer
name, address and/or STB ID based on personal information included
in the viewing record 400 (e.g., a STB ID 408), personal
information stored in another local database and referenced by data
included in the viewing record 400 (e.g., name, address and STB ID
information stored in a local database and indexed by the home unit
ID 404), etc.
[0073] After the processing at block 1014 completes, control then
proceeds to block 1016 at which the hashed metering database
processor 800 concatenates the formatted viewer name, address and
STB ID into a single bit string that identifies the viewer
corresponding to the viewing record 400. The hashed metering
database processor 800 inputs this concatenated bit string into a
cryptographic hashing function at block 1018 to generate a unique
hash ID corresponding to the particular viewer. As discussed above,
any well-known cryptographic hashing function may be employed at
block 1018. However, one having ordinary skill in the art will
recognize that the formatting performed by blocks 1006, 1010 and
1014, the concatenation performed by block 1016 and the hashing
function performed by block 1018 should match the corresponding
functionality used by the metering record hashing unit (e.g., the
metering record hashing unit 600) that generated the VOD server
hashed database (e.g., the VOD server hashed database 608) provided
as input to the example program 1000. Otherwise, the hash ID
generated at block 1018 will not correspond to the type of hash IDs
stored in the VOD server hashed database 608 and, thus, any attempt
to cross-reference the VOD server hashed database 608 with such a
generated hash ID will fail. Assuming that the hash ID generated at
block 1018 was based on the appropriate formatting, concatenation
and cryptographic hash function, control then proceeds to block 516
of FIG. 10B.
[0074] At block 516 of FIG. 10B the hashed metering database
processor 800 cross-references the VOD server hashed database 608
based on the unique hash ID generated at block 1018 of FIG. 10A.
Then, at blocks 520, 524 and 528 the hashed metering database
processor 800 may combine the VOD data reported in the viewing
record 400 with the corresponding, specific VOD content information
included in the VOD server hashed database 608 and corresponding to
the unique viewer hash ID. The functionality of blocks 516, 520,
524 and 528 is substantially similar to the corresponding blocks of
FIG. 5 and, thus, these blocks are not described in further detail
herein. After the processing performed at these blocks completes,
and the hashed metering database processor 800 appropriately
combines the viewing record 400 with the data included in the VOD
server hashed database 608, control proceeds to block 1020.
[0075] At block 1020 the hashed metering database processor 800
determines whether the viewing record 400 is the last viewing
record in the central facility metering database 812 to be
processed. If the viewing record 400 is not the last record to be
processed (block 1020), control returns to block 1002 of FIG. 10A
and blocks subsequent thereto at which the hashed metering database
processor 800 processes the next viewing record in the central
facility metering database 812. Conversely, if the viewing record
400 is the last record to be processed (block 1020), control
proceeds to block 1024 at which the central facility 328 generates
ratings/metering reports based on the potentially updated viewing
records 400 stored in the central facility metering database 812.
The example program 1000 then ends.
[0076] FIG. 11 is a block diagram of an example computer 1100
capable of implementing the apparatus and methods disclosed herein.
The computer 1100 can be, for example, a server, a personal
computer, a personal digital assistant (PDA), an Internet
appliance, or any other type of computing device.
[0077] The system 1100 of the instant example includes a processor
1112. For example, the processor 1112 can be implemented by one or
more Intel.RTM. microprocessors from the Pentium.RTM. family, the
Itanium.RTM. family or the XScale.RTM. family. Of course, other
processors from other families are also appropriate. One or more
processors such as processor 1112 may be used to implement any or
all of the home unit 124 and/or the STB 108 (or portions thereof)
of FIG. 1, the central facility processor 224 (or portions thereof)
of FIG. 2, the VOD server 304 and/or the metering server interface
324 of FIG. 3, the metering record hashing unit 600 of FIG. 6
and/or the hashed metering database processor 800 of FIG. 8. A
processor such as processor 1112 may also be used to implement the
example programs 900 and/or 1000 of FIGS. 9 and 10A-10B,
respectively.
[0078] The processor 1112 is in communication with a main memory
including a volatile memory 1114 and a non-volatile memory 1116 via
a bus 1118. The volatile memory 1114 may be implemented by Static
Random Access Memory (SRAM), Synchronous Dynamic Random Access
Memory (SDRAM), Dynamic Random Access Memory (DRAM), RAMBUS Dynamic
Random Access Memory (RDRAM) and/or any other type of random access
memory device. The non-volatile memory 1116 may be implemented by
flash memory and/or any other desired type of memory device. Access
to the main memory 1114, 1116 is typically controlled by a memory
controller (not shown) in a conventional manner.
[0079] The computer 1100 also includes a conventional interface
circuit 1120. The interface circuit 1120 may be implemented by any
type of well-known interface standard, such as an Ethernet
interface, a universal serial bus (USB), and/or a third generation
input/output (3GIO) interface.
[0080] One or more input devices 1122 are connected to the
interface circuit 1120. The input device(s) 1122 permit a user to
enter data and commands into the processor 1112. The input
device(s) can be implemented by, for example, a keyboard, a mouse,
a touchscreen, a track-pad, a trackball, an isopoint and/or a voice
recognition system.
[0081] One or more output devices 1124 are also connected to the
interface circuit 1120. The output devices 1124 can be implemented,
for example, by display devices (e.g., a liquid crystal display, a
cathode ray tube display (CRT)), by a printer and/or by speakers.
The interface circuit 1120, thus, typically includes a graphics
driver card.
[0082] The interface circuit 1120 also includes a communication
device such as a modem or network interface card to facilitate
exchange of data with external computers via a network 1126 (e.g.,
an Ethernet connection, a digital subscriber line (DSL), a
telephone line, coaxial cable, a cellular telephone system, etc.).
The interface circuit 1120 and the network 1126 may implement the
connection 140 of FIG. 1.
[0083] The computer 1100 also includes one or more mass storage
devices 1128 for storing software and data. Examples of such mass
storage devices 1128 include floppy disk drives, hard drive disks,
compact disk (CD) drives and DVD drives. The mass storage device
1128 and/or the volatile memory 1114 may be used to store the
viewing records in the home unit 124 of FIG. 1. A mass storage
device such as the mass storage device 1128 may also be used to
store the VOD server cleartext database 604 and/or the VOD server
hashed database 608 of FIG. 6.
[0084] As an alternative to implementing the methods and/or
apparatus described herein in a system such as the device of FIG.
11, the methods and or apparatus described herein may be embedded
in a structure such as a processor and/or an ASIC (application
specific integrated circuit).
[0085] Although certain example methods, apparatus and articles of
manufacture have been described herein, the scope of coverage of
this patent is not limited thereto. On the contrary, this patent
covers all methods, apparatus and articles of manufacture fairly
falling within the scope of the appended claims either literally or
under the doctrine of equivalents.
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