The present invention relates to market research methods and systems which gather data concerning the exposure of panelists to predetermined products.
Manufacturers and distributors of products, as well as service providers, expend substantial amounts in advertising and promotional activities for the purpose of stimulating interest in their products and services among consumers. They review sales volume information as well as more detailed purchasing information such as the demographic characteristics of those who purchase their products and services in order to select those advertisements and promotional activities which seem best suited to influence consumers to purchase their products and services.
It is desired, however, to obtain more detailed information concerning the effectiveness of advertising and promotional expenditures, and in particular to assess their effectiveness in stimulating initial interest in products and services among consumers whether or not they purchase them, since factors apart from advertising and promotion, such as price, affect the decision to purchase.
For this application the following terms and definitions shall apply:
The term “data” as used herein means any indicia, signals, marks, symbols, domains, symbol sets, representations, and any other physical form or forms representing information, whether permanent or temporary, whether visible, audible, acoustic, electric, magnetic, electromagnetic or otherwise manifested. The term “data” as used to represent predetermined information in one physical form shall be deemed to encompass any and all representations of the same predetermined information in a different physical form or forms.
The term “media data” as used herein means data which is widely accessible, whether over-the-air, or via cable, satellite, network, internetwork (including the Internet), distributed on storage media, or otherwise, without regard to the form or content thereof, and including but not limited to audio, video, text, images, animations, web pages and streaming media data.
The term “database” as used herein means an organized body of related data, regardless of the manner in which the data or the organized body thereof is represented. For example, the organized body of related data may be in the form of a table, a map, a grid, a list or in any other form.
The term “location” as used herein refers to a position relative to a commercial establishment, a product display, a product, another object or facility, or relative to a coordinate system such as latitude and longitude.
The term “layout map” as used herein means a database of data representing locations in an area or areas for purposes of market research.
The term “network” as used herein includes both networks and internetworks of all kinds, including the Internet, and is not limited to any particular network or inter-network.
The terms “first” and “second” are used to distinguish one element, set, data, object or thing from another, and are not used to designate relative position or arrangement in time.
The terms “coupled”, “coupled to”, and “coupled with” as used herein each mean a relationship between or among two or more devices, apparatus, files, programs, media, components, networks, systems, subsystems, and/or means, constituting any one or more of (a) a connection, whether direct or through one or more other devices, apparatus, files, programs, media, components, networks, systems, subsystems, or means, (b) a communications relationship, whether direct or through one or more other devices, apparatus, files, programs, media, components, networks, systems, subsystems, or means, and/or (c) a functional relationship in which the operation of any one or more devices, apparatus, files, programs, media, components, networks, systems, subsystems, or means depends, in whole or in part, on the operation of any one or more others thereof.
The terms “communicate” and “communication” as used herein include both conveying data from a source to a destination, and delivering data to a communications medium, system or link to be conveyed to a destination.
The term “processor” as used herein means processing devices, apparatus, programs, circuits, systems and subsystems, whether implemented in hardware, software or both.
The terms “storage” and “data storage” as used herein mean data storage devices, apparatus, programs, circuits, systems, subsystems and storage media serving to retain data, whether on a temporary or permanent basis, and to provide such retained data.
In accordance with an aspect of the present invention, a method is provided for monitoring exposure to a product of a participant in market research. The method comprises providing a portable monitor comprising a wireless receiver to a respective participant selected from a plurality of participants in the market research study, the portable monitor being adapted to be carried on the person of a participant; detecting product data in the portable monitor, the product data being contained in a product signal received in the wireless receiver from a predetermined signal transmitter proximal to a respective product, the product data representing the respective product, the product signal having a signal strength selected so that the product data is detectable by the portable monitor only when in a predetermined proximity to the predetermined signal transmitter; and storing the product data in the portable monitor.
In accordance with a further aspect of the present invention, a device is provided for monitoring exposure to products by participants in market research. The device comprises a portable monitor adapted to be carried on the person of a participant in the market research study, the portable monitor comprising a wireless receiver operative to receive a product signal from a predetermined signal transmitter proximal to a respective product, the product signal containing product data representing the respective product, the wireless receiver having a sensitivity selected so that the portable monitor is capable of detecting the product data in the product signal only when in a predetermined proximity to the predetermined signal transmitter; and a data storage coupled with the wireless receiver to receive and store the product data.
In accordance with another aspect of the present invention, a system is provided for monitoring exposure of a participant in market research to a predetermined product. The system comprises a database storing product location data representing a location of a predetermined product; a portable monitor adapted to be carried on the person of a participant in market research and comprising a position monitor operative to produce participant location data representing a location of the participant and a data storage coupled with the position monitor to receive the participant location data and operative to store the participant location data; and a processor coupled with the portable monitor to receive the participant location data therefrom and operative to access the product location data from the database; the processor serving to process the participant location data and the product location data produce product proximity data indicating exposure of the participant to the predetermined product.
The present invention is useful for monitoring the exposure of customers to products, but is particularly useful for gathering such data in retail stores as well as in all other kinds of commercial establishments.
An RF transmitter 40 is placed in the vicinity of a particular product offered for sale, here indicated as a fictitious product, Champs Chomp dog food. The RF transmitter 40 transmits a product signal containing data identifying the product of interest, its manufacturer, distributor and/or otherwise containing data corresponding to the product. Such data in certain embodiments comprises a transmitter identification code that uniquely identifies the transmitter 36, and from which data relating to the product can be obtained. In certain embodiments the product signal includes commercial establishment data identifying or otherwise relating to the commercial establishment in which the panelist is present. In certain embodiments, the commercial establishment data directly identifies the commercial establishment, while in others the commercial establishment data is used to access or derive such identity. In certain embodiments, the commercial establishment data relates to the commercial establishment, with or without identifying it directly or indirectly. The frequency or frequencies of the product signal can be selected from any permissible frequency range, up to and including microwave frequencies.
As the panelist wearing the portable monitor 32 draws near to the product, the monitor 32 receives the product signal and detects the data contained therein. The strength of the transmitted product signal, along with the sensitivity of the monitor 32 are selected to ensure that monitor 32 will only detect the data contained in the product signal when it is sufficiently near the predetermined product for the purposes of the study. In certain advantageous embodiments, one or both of the strength of the location signal and the sensitivity of the monitor are selected to ensure that the monitor 32 will only detect the data in the product signal when the monitor is located within a predetermined area to be monitored, such as a predetermined area in which the predetermined product or a product display containing the product can be perceived by the panelist. When the monitor 32 detects the data contained in the product signal, it stores either the data or data based thereon, together with a time stamp indicating the time at which the data was received.
If the panelist lingers in the vicinity of transmitter 40, this indicates that the panelist may be interested in purchasing the adjacent product. Accordingly, periodically or from time to time the monitor 32 checks for the detection of the data contained in the same or a different product signal. If the data of the same product signal has again been detected, the monitor 32 stores further data indicating a duration of the continuous presence of the panelist in the vicinity of transmitter 40.
In certain embodiments, the transmitter 40 cooperates with an intelligent shelf system of the commercial establishment to gather product data.
Where the product signal transmitted by the transmitter 40 contains transmitter identification data, this transmitter identification data is also stored in a database where it is associated with data identifying the product or otherwise relating to it.
A first record 48 of the
A further record 52 of the
As the panelist proceeds through the store, the monitor 32 detects data contained in further product signal indicating that the panelist has approached another predetermined product involved in the study. The detected data is stored by the monitor 32 in a record such as exemplary record 74 shown in
In the transmitter embodiment 86, power from the power source 110 is only applied to the RF transmitter 90 and code modulator 98 when the proximity detector 102 detects the presence of a person in proximity to the transmitter 86 and turns on the normally off power switch 106. The proximity detector 102 senses a selected form or forms of data indicating the presence or approach of a person, such as changes or levels of infrared, thermal, light, or electrical energy, and then provides a switching signal to power switch 106 to turn it on. In certain embodiments an external switch is employed to switch on power, such as a pressure sensitive switch activated by the panelist's footstep or a doorway switch actuated by opening a door or passing through a doorway. Preferably power switch 106 remains on only long enough to ensure that a detectable product signal is transmitted to any monitor 32 that may be carried by a panelist nearby, so that power from the source 110 is conserved to ensure the continuing ability of the transmitter 86 to function. As an example only, in certain embodiments the power switch applies power continuously for 30 seconds after receipt of the switching signal and then automatically resets to an off state, so that the product signal is transmitted continuously for such 30 second period. In certain embodiments, the transmitter has two operational states, a standby, low power mode in which it does not transmit and a transmit mode in which it does. In such embodiments, the switch 106 or other circuitry switches the transmitter from the standby mode to the transmit mode when a person's proximity is detected.
The RF transmitter 90 drives antenna 94 to transmit an RF product signal within an appropriate band selected as any permissible RF band up to and including microwave frequencies. In certain embodiments the RF transmitter 90 produces the product signal in an unlicensed 900 MHz band and at a sufficiently low power level so that its data will be detectable by monitor 32 only within a relatively short range.
The data contained by the product signal is produced by code modulator 98 and applied as a modulating signal by code modulator 98 to RF transmitter 90. The product signal can be modulated in any manner that is compatible with the detection capabilities of portable monitor 32, such as by amplitude, frequency, pulse or phase modulation or any combination thereof. In certain embodiments the data is simply represented by the frequency of the product signal, so that a separate code modulator is not required. In certain embodiments, the data modulates the product signal to produce a periodically repeating code. As an example, such a code could repeat every 10 seconds during the transmission of the product signal, although a different repetition rate could be selected depending on the amount of data that must be transmitted and the detection error rate of the personal monitor 32 within the desired detection area.
The power source 110 is selected as one that is capable of supplying sufficient power for a desired duration, such as the duration of the marketing study. The power source 110 in certain embodiments is selected as a rechargeable battery, a non-rechargeable battery, an energy storage device, a photoelectric power source and/or a different energy receiving device such as an antenna receiving energy from the portable monitor 32 or other external source.
In certain embodiments rather than transmit upon detection of a person in proximity to the transmitter 86, the RF transmitter 90 transmits the product signal periodically. In still other embodiments the RF transmitter 90 transmits the product signal in response to a query signal transmitted from a transmitter included in the portable monitor 32 (not shown for purposes of simplicity and clarity). In certain embodiments, the transmitter is an RFID tag that receives a read signal from the monitor 32, and uses the energy of the received read signal to encode its data and retransmit the encoded data as a location signal. In certain ones of such embodiments, the RFID tag is affixed to the product itself or its packaging. In embodiments which employ RFID tags, it is advantageous to selectively key the monitor on to transmit such read signal as infrequently as possible, due to the relatively large amount of energy that must be transmitted by the monitor 32 to energize the RFID tag to retransmit a detectable product signal. For this purpose, in certain embodiments a transmitter is provided in or near the commercial establishment to key the monitor to transmit the read signal.
In certain embodiments, one or more RF energy emitters separate from the monitors 32 are placed in or near the store or other commercial establishment to emit RF energy to be received by one or more nearby RFID tags in order to energize them to transmit their codes. When a panelist carrying a monitor 32 comes within range of one of such RFID tags, the monitor detects its code and stores appropriate data. In certain embodiments, the RF energy emitters emit RF energy continuously. In others, the RF energy emitters emit RF energy periodically, from time to time, at certain times or during certain time periods. In still other embodiments, the RF energy emitters emit RF energy upon detecting either a presence of a person or of a monitor 32.
In still other embodiments, transmitters provided with an active power source, such as a battery, photoelectric cell or the like, are affixed to the product itself or its packaging, rather than attached to or placed on or in a nearby shelf or other fixture.
In other embodiments in place of an RF transmitter 90, the transmitter 86 employs a different type of wireless transmitter, such as an infrared, visible light or acoustic transmitter. An appropriate acoustic product signal emitter for this purpose is disclosed in U.S. published patent application 20030171833 A1 in the names of Jack C. Crystal and James M. Jensen, assigned to the assignee of the present application and hereby incorporated in its entirety herein by reference.
RF receiver 114 has an input coupled with antenna 118 to receive the product signal and is operative to detect the data therein and supply it at an output coupled with processor 130 in a form suitable for input to the processor 130. Preferably, the receiver 114 is operated only periodically, or from time to time, in order to conserve power in the portable monitor 32. For example, in certain embodiments the receiver 144 is turned on for a 10 second period during a repeating 30 second interval.
Where the transmitter 86 transmits the product signal in a different form, such as infrared or visible light, wireless receiver 114 and antenna 118 are replaced in other embodiments of the portable monitor 32 by a suitable light sensor and conditioning circuitry coupled with the light sensor and operative to detect the data contained in the product signal and supply it in a suitable form to the processor 130. Where the transmitter 86 instead transmits an acoustic product signal, in certain embodiments of portable monitor 32 the microphone 122 and conditioning circuitry 126 serve to receive the product signal and supply it in suitable form to the processor 130. In certain ones of such embodiments the processor 130 serves to detect the data contained in the product signal transmitted in acoustic form.
The processor 130 is also operative to store the detected product data with a time stamp produced by processor 130 or else by a separate clock (not shown for purposes of simplicity and clarity). Where the processor continues to detect the same product signal data, in certain embodiments it produces duration data indicating a duration of continuous receipt of the same product signal data and stores it in association with the location data and time stamp. In certain other embodiments, in place of duration data, the processor instead stores an ending time stamp representing a point in time when it no longer continues to receive the same product signal data. In still other embodiments, the processor simply stores each detection of the product signal data with a respective time stamp associated therewith.
The embodiments of portable monitor 32 illustrated in
In certain embodiments, a commercial establishment signal is transmitted to the monitor 32 by a transmitter other than those employed as in
In still other embodiments, an acoustic transmitter is employed to transmit the commercial establishment signal. An embodiment of such an acoustic transmitter is illustrated in
Acoustic transmitter 112 also comprises an encoder 120 which receives the audio from source 116 and encodes the commercial establishment data therein. Encoder 120 evaluates the ability of the received audio to mask the data when encoded in the audio and produces or adjusts the level, frequency, phase and/or other characteristic of the data to be encoded or as encoded, so that the code is inaudible when the audio is reproduced as sound. The encoded audio is output by the encoder 120 to a speaker 124 which emits the encoded audio as acoustic energy.
The encoder 120 in certain embodiments comprises an encoder of the kind disclosed in U.S. patent application Ser. No. 10/302,309 in the names of James M. Jensen and Alan R. Neuhauser, assigned to the assignee of the present application and incorporated herein by reference in its entirety and/or of the kind disclosed in U.S. Pat. No. 5,764,763 in the names of James M. Jensen, et al, assigned to the assignee of the present application and incorporated herein by reference in its entirety.
In certain embodiments the audio supplied from the source 116 is already encoded with the commercial establishment signal, for example, by encoding the audio and storing it for later reproduction. In still other embodiments, rather than encode an audio signal the acoustic transmitter samples the ambient acoustic energy to evaluate its ability to mask the commercial establishment signal and emits the commercial establishment signal having appropriate characteristics to ensure that the ambient acoustic energy will mask it. Embodiments of such acoustic transmitters are disclosed in U.S. published patent application 20030171833 A1, mentioned above.
In certain embodiments of the present invention which employ acoustic transmitters to transmit product signals and/or commercial establishment signals, the personal monitor 32 employs the microphone 122 to receive such acoustic signals and detects the data therein by means of the processor 130. In certain ones of such embodiments, the processor 130 advantageously employs a detection technique disclosed in U.S. Pat. No. 5,764,763, mentioned above, to detect the data encoded in the various acoustic signals.
In certain embodiments, acoustic transmitters are employed both to emit product signals within a commercial establishment, but also to transmit a commercial establishment signal. In such embodiments it is possible to dispense with the use of an RF receiver in monitor 32.
In certain embodiments wherein the product signal transmitters comprise acoustic transmitters, the acoustic transmitters transmit acoustic signals containing both product data and commercial establishment data to the monitor 32 which detects and stores both of these data from the received acoustic signal. In certain advantageous embodiments, both the product data and the commercial establishment data are encoded and detected according to techniques disclosed in U.S. patent application Ser. No. 10/302,309, mentioned above. In one such encoding technique, the product data and commercial establishment data are transmitted repeatedly, but each has a different duration. The monitor 32 employs two accumulators, one of which is a register having a length selected to accumulate the product data and the other of which is a different register having a length selected to accumulate the commercial establishment data. Although components of each of the data are accumulated in both registers, a register having a length selected to accumulate the product data, for example, will additively accumulate components of the product data, but will not accumulate corresponding components of the commercial establishment data, so that the commercial establishment data will appear as noise in this register.
In certain embodiments portable monitor 32 serves to monitor exposure to outdoor advertising in settings such as highways, railways, and walkways, malls, subways, railway stations, bus stations, airports and building lobbies.
In certain embodiments receiver 114 of portable monitor 32 is arranged to receive the billboard proximity signal and detect the billboard proximity data therein. In other embodiments, a different wireless receiver is included in monitor 32 for this purpose. Further embodiments of media display exposure monitoring means suitable for use in monitor 32 are disclosed in U.S. patent application Ser. No. 10/329,132 in the names of Jack K. Zhang, Jack C. Crystal and James M. Jensen, assigned to the assignee of the present application and hereby incorporated by reference herein in its entirety. Still further embodiments of media display exposure monitoring means suitable for use in monitor 32 are disclosed in U.S. patent application Ser. No. 10/640,104 in the names of Jack K. Zhang, Jack C. Crystal, James M. Jensen and Eugene L. Flanagan III, assigned to the assignee of the present application and hereby incorporated by reference herein in its entirety.
Once the data has been downloaded, the memory 134 of the monitor 32 is reset to store further data. The base stations may be, for example, those disclosed in U.S. Pat. No. 5,483,276 to Brooks, et al., assigned to the assignee of the present invention and hereby incorporated herein by reference in its entirety. The base stations 150, 154 communicate with a communications hub 158 also located in the household for communication via a network 162 to the centralized processor 166 located remotely from the household. The centralized processor 166 likewise receives data from other panelists' households to produce reports as mentioned above.
The centralized processor 166 stores the received data in one or more databases from which it is accessed to produce such reports. A relational database for use in storing the downloaded data gathered by monitors 32 in various commercial establishments, for use in producing reports concerning exposure to products in such commercial establishments, is now described with reference to
In certain embodiments, the table of
In certain embodiments, the data used to populate the table of
As described above,
In certain ones of such reports, the exposure data of
As noted above, in certain embodiments of the personal monitors 32, not only is such data gathered but also data indicating exposure to media data such as television and radio broadcast exposure, as well as exposure to media displays, both outdoor and indoor. The systems and methods of the present inventions thus provide integrated data estimating not only exposure of consumers to products but also exposure of such consumers to media data and the advertisements conveyed thereby. It is thus possible to evaluate the effects of the exposure to advertising of predetermined individuals to their interest in particular products that may be stimulated by such advertising.
Further embodiments of a system and method for monitoring exposure of a panelist to one or more products within a commercial establishment in accordance with certain embodiments of the present invention are now described. In certain embodiments the receiver 114 of portable monitor 32 (
In certain other embodiments the portable monitor transmits a signal that is received by one or more receiving devices within or near the commercial establishment to determine the location of the portable monitor. In still other embodiments, the portable monitor includes a cellular telephone module (not shown for purposes of simplicity and clarity) that communicates with a cellular telephone system to obtain data therefrom representing the location of the portable monitor 32 based on signals received from the cellular telephone module. Such location data is provided as latitude and longitude or in another usable form. In still further embodiments, the portable monitor 32 employs at least one of the following techniques to generate the location data: an angle of arrival (AOA) technique, a time difference of arrival (TDOA) technique, an enhanced signal strength (ESS) technique, a location fingerprinting technique, and an ultra wideband location technique. From such location data, the exposure of the panelist to one or more products at or near the location represented by the location data is inferred or assessed. Each of these techniques is now briefly described.
The angle of arrival (AOA) technique determines the direction of a signal received from a radio frequency (RF) transmitter. This can be done by pointing a directional antenna along the line of maximum signal strength. Alternatively, signal direction can be determined from the difference in time of arrival of the incoming signals at different elements of the antenna. A two-element antenna is typically used to cover angles of ±60 degrees. To achieve 360-degree coverage, a six-element antenna can be used. However, a single mobile directional antenna can give only the bearing, not the position, of a transmitting object.
With two directional antennas spaced well apart, however, the position of a transmitting device in a plane can be computed. In this method, also known as the angle of arrival (AOA) method, transmitter position is determined from the known (fixed) position of the receivers' antennas and the angle of arrival of the signals with respect to the antennas. In certain embodiments the portable monitor 32 includes a transmitter that enables its location to be determined in accordance with the angle of arrival method.
The time difference of arrival (TDOA) technique is based upon the similar concept that the difference in time of arrival between signals received at antennas at different locations can be used to determine position. Given the speed of light and known transmit and receive times, the distance between a transmitter and the receiver antenna can be calculated. In certain embodiments the portable monitor 32 includes a transmitter that enables its location to be determined in accordance with the time difference of arrival technique.
In an alternative time difference scheme, the monitor and the antennas reverse roles: the antennas are transmitters and the portable monitor 32 incorporates a receiver. This technique is known as forward link trilateration (FLT). This is relatively simple to implement in some code-division multiple access (CDMA) wireless systems, where the time difference of arrival can be determined from the phase difference between pseudo-random noise code sequences of 0s and 1 s transmitted from two antennas. In certain embodiments the portable monitor 32 includes a receiver, such as a CDMA cellular telephone receiver, that enables its location to be determined in accordance with the forward link trilateration method.
When the term “time difference of arrival technique” is used herein, the term is meant to encompass both the traditional time difference of arrival (TDOA) method and the forward link trilateration (FLT) method.
The enhanced signal strength (ESS) method provides improvements over conventional signal strength methods by overcoming such impediments as multipath effects, attenuation, and antenna orientation. The method involves taking in three-dimensional information on the objects, walls, and other features and obstructions within the commercial establishment, and using such information to simulate the RF signal propagation characteristics of wireless transmitting antennas in the area. A location system center stores the results in an RF database. The position of the portable monitor is determined by getting it to measure the signal strength of preferably three to five base transmitters. From this input plus information from the database, the system can calculate the position of the portable monitor. Inside large commercial establishments, such as malls and department stores with appropriate base transmitters located therein, the position of a portable monitor can be determined by means of the ESS method. In certain embodiments the portable monitor 32 includes a receiver that enables its location to be determined in accordance with the ESS method.
The location fingerprinting technique, instead of exploiting signal timing or signal strength, relies on signal structure characteristics. The technique turns the multipath phenomenon to good use by combining the multipath pattern with other signal characteristics, to create a signature unique to a given location. A location fingerprinting system includes a signal signature database of a location grid for a specific area. To generate this database, a device is walked through the area transmitting or receiving signals to or from a monitoring site. The system analyzes the incoming signals, compiles a unique signature for each square in the location grid, and stores it in the database.
To determine the position of a mobile transmitter or receiver, the system matches the transmitter's or receiver's signal signature to an entry in the database. Multipoint signal reception is not required, although it is preferable. The system can use data from only a single point to determine location. In certain embodiments the portable monitor 32 includes a transmitter or a receiver that enables its location to be determined in accordance with the location fingerprinting technique.
In certain ultra wideband location techniques a network of localizers determine relative locations in three-dimensional space by measuring propagation times of pseudorandom sequences of electromagnetic impulses. The propagation time is determined from a correlator which provides an analog pseudo-autocorrelation function sampled at discrete time bins. The correlator has a number of integrators, each integrator providing a signal proportional to the time integral of the product of the expected pulse sequence delayed by one of the discrete time bins, and the non-delayed received antenna signal. Using pattern recognition the arrival time of the received signal can be determined to within a time much smaller than the separation between bins.
In certain ultra wideband techniques, wireless ultra wideband transceivers are positioned at known stationary locations within the area to be monitored, and the portable monitor 32 includes a wireless ultra wideband receiver/processor that receives one or more timed pulses from the various transceivers and resolves the location of the portable monitor within the monitored area based on the locations of the ultra wideband transceivers and time-of-flight measurements of the pulse or pulses. In certain embodiments, the portable monitor 32 includes an ultra wideband transmitter and a plurality of interacting receivers in stationary positions receive a pulse from the transmitter of the portable monitor 32 to determine its location. In certain of the embodiments, the stationary transceivers or receivers are coupled by cabling, while in others they are untethered.
Referring now to
In the embodiment of
The inertial monitoring device preferably is small in size and lightweight. An advantageous embodiment of such an inertial monitoring device employs microelectromechanical sensors (MEMS) as either gyroscopic sensors and/or accelerometers to provide data from which the location of the monitor can be determined.
In certain embodiments to calibrate the inertial monitoring device 200 the portable monitor 204 employs satellite-based techniques, such as global positioning system (GPS) and/or server assisted GPS technology, and/or terrestrial techniques, such as an angle of arrival (AOA) technique, a time difference of arrival (TDOA) technique, an enhanced signal strength (ESS) technique, a location fingerprinting technique, and/or an ultra wideband location technique.
For certain embodiments which gather location data by means of a portable monitor, a database similar to that of
Although various embodiments of the present invention have been described with reference to a particular arrangement of parts, features and the like, these are not intended to exhaust all possible arrangements or features, and indeed many other embodiments, modifications and variations will be ascertainable to those of skill in the art.