US010341811B2
`
`( 12 ) United States Patent
`Shkedi
`
`( 10 ) Patent No . : US 10 , 341 , 811 B2
`( 45 ) Date of Patent :
`* Jul . 2 , 2019
`
`( * ) Notice :
`
`( 54 ) SIGNAL COMPARISON - BASED LOCATION
`DETERMINING METHOD
`( 71 ) Applicant : Broadphone , LLC , New York , NY
`( US )
`( 72 ) Inventor : Roy Shkedi , Forest Hills , NY ( US )
`( 73 ) Assignee : Broadphone , LLC , New York , NY
`( US )
`Subject to any disclaimer , the term of this
`patent is extended or adjusted under 35
`U . S . C . 154 ( b ) by 906 days .
`This patent is subject to a terminal dis
`claimer .
`( 21 ) Appl . No . : 14 / 085 , 603
`( 22 ) Filed :
`Nov . 20 , 2013
`Prior Publication Data
`( 65 )
`US 2014 / 0073353 A1 Mar . 13 , 2014
`Related U . S . Application Data
`( 63 ) Continuation of application No . 13 / 448 , 309 , filed on
`Apr . 16 , 2012 , now Pat . No . 8 , 594 , 698 , which is a
`( Continued )
`
`( 52 )
`
`( 51 ) Int . Ci .
`H04W 24 / 00
`( 2009 . 01 )
`H04W 4 / 02
`( 2018 . 01 )
`GOIS 5 / 02
`( 2010 . 01 )
`U . S . CI .
`CPC . . . . . . . . . H04W 4 / 023 ( 2013 . 01 ) ; GOIS 5 / 0252
`( 2013 . 01 )
`( 58 ) Field of Classification Search
`CPC . . H04W 4 / 02 ; H04W 64 / 00 ; HO4L 29 / 08657 ;
`H04L 29 / 08108 ; HO4L 29 / 08936 ;
`( Continued )
`
`( 56 )
`
`EP
`WO
`WO
`
`References Cited
`U . S . PATENT DOCUMENTS
`1 / 2004 Gray et al .
`6 , 674 , 403 B2
`12 / 2005 Sollenberger et al .
`6 , 972 , 717 B2
`( Continued )
`FOREIGN PATENT DOCUMENTS
`12419093
`9 / 2002
`3 / 2000
`WO 00 / 18148 Al
`WO 01 / 28272 A1
`4 / 2001
`
`OTHER PUBLICATIONS
`Krumm , et al . ; LOCADIO : Inferring Motion and Location from
`Wi - Fi Signal Strengths ; 1st Annual International Conference on
`Mobile and Ubiquitous Systems : Networking and Services ; Aug .
`22 - 26 , 2004 .
`
`( Continued )
`Primary Examiner – Dai Phuong
`( 74 ) Attorney , Agent , or Firm — Louis J . Hoffman
`( 57 )
`ABSTRACT
`At least one portable RF communications device in con
`junction with at least two fixed - location service - area antenna
`stations respectively capable of RF communication with the
`at least one device performs the steps of : ( I ) using a portable
`device at a selected location to measure RF communications
`signals from the plurality of local fixed - location service - area
`antenna stations and electronically storing at least two of the
`respective reception signal strength measurements ; and ( II )
`monitoring a portable device location by causing the device
`to measure reception signal strength associated with local
`fixed - location service - area antenna stations signals , and to
`electronically compare these measurements with the stored
`at least two measurements .
`28 Claims , 1 Drawing Sheet
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`210
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`Mart
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`200
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`MAR RUM
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`220
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`Page 1 of 18
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`US 10 , 341 , 811 B2
`Page 2
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`( 58 )
`
`( 56 )
`
`Related U . S . Application Data
`continuation of application No . 12 / 720 , 362 , filed on
`Mar . 9 , 2010 , now Pat . No . 8 , 170 , 583 , which is a
`continuation of application No . 11 / 533 , 238 , filed on
`Sep . 19 , 2006 , now Pat . No . 7 , 706 , 811 .
`Field of Classification Search
`CPC . . . . . . . . . . . . GO1S 5 / 0252 ; GOIS 5 / 02 ; GOIS 5 / 14 ;
`H04M 1 / 72572 ; G01C 21 / 20
`USPC . . . . . . . . 455 / 404 . 2 , 432 . 1 , 436 , 437 , 440 , 441 ,
`455 / 452 . 2 , 456 . 1 , 456 . 2 , 513
`See application file for complete search history .
`References Cited
`U . S . PATENT DOCUMENTS
`4 / 2006 de Verteuil
`7 , 035 , 647 B2
`7 , 050 , 786 B2
`5 / 2006 Caci
`6 / 2006 Hall et al .
`7 , 057 , 556 B2
`7 , 096 , 030 B2
`8 / 2006 Huomo
`9 / 2006 Bar - On et al .
`7 , 102 , 570 B2
`7 , 305 , 245 B2
`12 / 2007 Alizadeh - Shabdiz et al .
`7 / 2008 Morgan et al .
`7 , 403 , 762 B2
`7 , 414 , 988 B2
`8 / 2008 Jones et al .
`10 / 2008 Morgan et al .
`7 , 433 , 694 B2
`7 , 471 , 954 B2
`12 / 2008 Brachet et al .
`1 / 2009 Morgan et al .
`7 , 474 , 897 B2
`2 / 2009 Morgan et al .
`7 , 493 , 127 B2
`3 / 2009 Morgan et al .
`7 , 502 , 620 B2
`4 / 2009 Alizadeh - Shabdiz et al .
`7 , 515 , 578 B2
`6 / 2009 Alizadeh - Shabdiz et al .
`7 , 551 , 579 B2
`7 , 551 , 929 B2
`6 / 2009 Alizadeh - Shabdiz et al .
`9 / 2009 Jagadeesan et al .
`7 , 593 , 722 B2
`7 , 640 , 288 B2
`12 / 2009 Yao et al .
`7 , 764 , 231 B1
`7 / 2010 Karr et al .
`B2
`8 / 2010 Alizadeh - Shabdiz
`
`8 / 2010 Alizadeh - Shabdiz et al .
`7 , 769 , 396 B2
`10 / 2010 Alizadeh - Shabdiz et al .
`7 , 818 , 017 B2
`11 / 2010 Alizadeh - Shabdiz et al .
`7 , 835 , 754 B2
`8 , 073 , 565 B2 12 / 2011 Johnson
`8 , 131 , 464 B23 / 2012 Farmer et al .
`2004 / 0203863 A1 * 10 / 2004 Huomo . . . . . . . . . . . . . . . . . HO4W 4 / 02
`455 / 456 . 1
`10 / 2004 Budka et al . . . . . . . . . . . . . 455 / 456 . 1
`2004 / 0203912 A1 *
`2005 / 0143068 A1 6 / 2005 Ben - Yehuda et al .
`701 / 213
`2006 / 0129317 A1 *
`6 / 2006 Farmer et al .
`2006 / 0154644 Al *
`7 / 2006 Erskine . . . . . . . . . . . . . . . . . H04W 48 / 04
`455 / 405
`2007 / 0010260 A1 *
`1 / 2007 Zellner . . . . . . . . . . . . . . . . . . . H04L 41 / 12
`455 / 456 . 1
`2007 / 0184852 AL
`8 / 2007 Johnson et al .
`2008 / 0039114 AL
`2 / 2008 Phatak et al .
`2009 / 0305705 Al 12 / 2009 Black
`
`OTHER PUBLICATIONS
`Bahl , et al . , RADAR : An In - Building RF - based User Location and
`Tracking System ; IEEE INFOCOM 2000 ; Mar . 26 , 2000 ; pp .
`775 - 784 .
`Motorola , Inc . , Overview of 2G LCS Technologies and Standards
`( 3GPP TSG SA2 LCS Workshop LCS - 010019 — London , UK , Jan .
`11 - 12 , 2001 ) .
`Y . Zhao , “ Mobile Phone Location Determination and Its Impact on
`Intelligent Transportation Systems , ” IEEE Transactions on Intelli
`gent Transportation Systems , vol . 1 , No . 1 , pp . 55 - 65 , Mar . 2000 .
`A Survey and Taxonomy of Location Systems for Ubiquitous
`Computing by Jeffrey Hightower and Gaetano Borriello ( Techni
`cal Report UW - CSE Jan . 8 , 2003 ) .
`SpotON : An Indoor 3D Location Sensing Technology Based on RF
`Signal Strength - by Jeffrey Hightower and Gaetano Borriello ( UW
`CSE Technical Report # 2000 - 02 - 02 , Feb . 18 , 2002 ) .
`* cited by examiner
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`Page 2 of 18
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`U . S . Patent
`
`Jul . 2 , 2019
`
`US 10 , 341 , 811 B2
`
`Figure 1
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`Figure 4
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`Figure 5
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`Figure 6
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`Figure 7
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`100 + 110
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`200
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`BA
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`220
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`300 ~ 310 ? 320 — 330
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`400
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`500 ? 510
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`520
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`530
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`600 + ? 610 + ? 620 +
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`630
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`Page 3 of 18
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`US 10 , 341 , 811 B2
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`5
`
`SIGNAL COMPARISON - BASED LOCATION
`DETERMINING METHOD
`
`Methods that involve the cellular network participation
`include :
`Cell - ID
`TDOA – Time Difference Of Arrival
`CROSS - REFERENCE TO RELATED
`TOA – Time Of Arrival
`APPLICATIONS
`AOA — Angel Of Arrival
`EOTD - Enhanced Observed Time Difference
`This application is a continuation of Ser . No . 13 / 448 , 309 ,
`A - FLT — Advanced Forward Link Trilateration
`filed Apr . 16 , 2012 , now U . S . Pat . No . 8 , 594 , 698 , which is
`A - GPS - Assisted GPS ( Global Positioning System )
`a continuation of application Ser . No . 12 / 720 , 362 , filed Mar .
`Methods that rely solely on the handset to determine its
`9 . 2010 . now U . S . Pat . No . 8 . 170 . 583 . which is a continu - 10
`position :
`ation of application Ser . No . 11 / 533 , 238 , filed Sep . 19 , 2006 ,
`GPS Global Positioning System
`now U . S . Pat . No . 7 , 706 , 811 . The disclosures of said appli
`Expect Cell - ID where the location of the handset is
`cations and their entire file wrappers ( included all prior art
`simply determined to be within the area of the cell , where the
`references cited therewith ) are hereby specifically incorpo -
`rated herein by reference in their entirety as if set forth fully 15 cell ' s base station location is known and the accuracy
`herein . Furthermore , a portion of the disclosure of this patent
`depends on the size of the cell ( accuracy of anywhere
`document contains material which is subject to copyright
`between 100 meter and 3 , 000 meters ) all other methods
`protection . The copyright owner has no objection to the
`require different levels of calculations either by the network
`facsimile reproduction by anyone of the patent document or
`or the handset or both .
`the patent disclosure , as it appears in the Patent and Trade - 20
`A substantially similar field where virtually the same class
`mark Office patent file or records , but otherwise reserves all
`of location based need arise is in the area of ubiquitous
`computing . Essentially , with respect to location based appli
`copyright rights whatsoever .
`cations , the primary difference between the mobile tele
`phony and ubiquitous computing relates to privacy — since
`TECHNICAL FIELD
`25 the mobile telephone user might prefer not to allow his
`The present invention generally relates to methods for
`location to be monitored , while privacy is a non - issue for a
`determining the location of a mobile telephone , or of a
`ubiquitous computer attached to a box in a large warehouse
`mobile communications device . More specifically , the pres
`or to a piece of luggage in an airport customs clearance
`ent invention relates to a method for determining the loca -
`center or to a semi - assembled component in a multifaceted
`tion of a mobile telephone , wherein the mobile telephone is 30 manufacturing facility or to a semiautonomous vehicle in a
`preferably capable of performing measurements of signal
`recreation center , etc .
`characteristics deriving from signals being received from
`A Survey and Taxonomy of Location Systems for Ubiq
`mobile telephone service area antennas , of performing cal -
`uitous Computing — by Jeffrey Hightower and Gaetano Bor
`culations related thereto , and of storing these measurements
`riello ( Technical Report UW - CSE 01 - 08 - 03 ) — “ Emerging
`35 mobile computing applications often need to know where
`and / or calculation results .
`things are physically located . To meet this need , many
`different location systems and technologies have been devel
`BACKGROUND ART
`oped . In this paper we present the basic techniques used for
`Simply stated , there is a longstanding problem of provid
`location - sensing , describe a taxonomy of location systems ,
`ing high accuracy location data for mobile devices , such as 40 present a survey of research and commercial location sys
`mobile telephones . In the most critical aspect , the problem
`tems that define the field , show how the taxonomy can be
`is to maintain user privacy of precise location data of the
`used to evaluate location - sensing systems , and offer sugges
`mobile telephone user . Nevertheless , there also remains a
`tions for future research . It is our hope that this paper is a
`need in the art for simple straightforward improvements in
`useful reference for researchers and location - aware applica
`determining the precise location of mobile devices ; espe - 45 tion builders alike for understanding and evaluating the
`cially in poor signal - reception locations such as in dense
`many options in this domain . "
`multi - story urban centers . Furthermore , there is a need in the
`SpotON : An Indoor 3D Location Sensing Technology
`art for providing an elevation component to location data , so
`Based on RF Signal Strength — by Jeffrey Hightower and
`as to locate a device in a multi - story structure .
`Gaetano Borriello
`( UW CSE Technical Report # 2000 - 02
`Motorola , Inc . , Overview of 2G LCS Technologies and 50 02 ) “ Providing a reliable technology and architecture for
`Standards ( 3GPP TSG SA2 LCS Workshop LCS -
`determining the location of real world objects and people
`010019 - London , UK , 11 - 12 Jan . 2001 ) discusses why
`will undoubtedly enable applications , customization , and
`locating mobile phones becomes a hot topic in telecom -
`inference not currently possible . This paper documents the
`munications industry , and what technologies are being
`creation of SpotON , a new tagging technology for three
`studied and standardized .
`55 dimensional location sensing based on radio signal strength
`Y . Zhao , “ Mobile Phone Location Determination and Its
`analysis . Although there are many aspects to the topic of
`Impact on Intelligent Transportation Systems , ” IEEE
`location sensing and several of them will be briefly dis
`Transactions on Intelligent Transportation Systems , vol .
`cussed , this paper is primarily concerned with the hardware
`1 , no . 1 , pp . 55 - 64 , March 2000 . — provides more infor -
`and embedded system development of such a system . ”
`mation on different location technologies and related 60
`For many mobile telephone location based services , con
`stant calculation of a user ' s handset location is required . For
`location services .
`There are many location - determining methods used to
`example , if a user asked to receive food coupons whenever
`determine the location of a cell phone . These methods differ
`he enters a specific area or to be informed if a child carrying
`in the level of accuracy they provide as well as their
`a cell phone left a certain perimeter around the house , or if
`implementation . In general these methods could be divided 65 the user asked for a group call to his cell phone and home
`into methods that involve the cellular network participation
`phone every time that he is at home ; in order to give him the
`and those that don ' t ( handset based only ) .
`option to answer calls to his cell phone on his landline .
`
`Page 4 of 18
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`US 10 , 341 , 811 B2
`
`assumed for the wireless communications device and the
`From a network perspective , in an anticipated emerging
`distance difference of arrival ( the time difference of arrival
`world where Location Based Services ( LBS ) are expected to
`multiplied by the speed of light ) is calculated . The calculated
`be widely used and of those services many require constant
`time difference of arrival is then used to adjust the distance
`monitoring of a user ' s cell phone location , those methods
`will require the networks to have a lot of infrastructure 5 difference of arrival by continuously iterating the position of
`dedicated to the determination of handsets ' locations .
`the wireless communications device until the calculated
`From a privacy perspective , having the cellular network
`distance of arrival and the calculated time difference of
`constantly monitor a user ' s location is problematic to many
`arrival ( as multiplied by the speed of light ) are within a
`people . For example , the user asked to receive coupons for
`predetermined margin . ”
`merchandise on sale when he is in the shopping area next to 10
`US Pat No 7050 786 _ Method And Apparatus For
`his home . However , that same user is troubled by a prospect
`Locating A Wireless Device — “ Disclosed is a method and
`that , in order for the coupons to be sent , the user ' s location
`apparatus for locating a wireless device especially useful for
`must be constantly monitored so as to find out when he
`locating a cellular telephone making a call from an unknown
`enters the shopping area .
`location . The call may be a request for emergency assis
`Obviously the privacy problem could be solved by having 15 loca
`tance , or for location - based commercial services , for
`the cell phone itself monitor its position , and activate an
`application when the cell phone concludes that the user has
`example . Various embodiments may optionally include a
`entered the shopping area , etc . This class of solution is also
`mobile location component , a cellular telephone enabled to
`chirp - on - demand , and / or an interferometer link . A mobile
`amenable for adaptation to ubiquitous computing situa
`tions — since it simply makes the location monitoring logic 20 location component may include a directional antenna . The
`directional antenna may be mounted on an antenna boom on
`part of a distributed computing architecture .
`Having the cell phone monitor its position will also
`top of an emergency vehicle , for example . The mobile
`location component may alternately or additionally com
`significantly reduce the infrastructure required by the cellu -
`lar network to determine the location of handsets . This is
`prise a hand - held unit . System elements may cooperate to
`also true in ubiquitous computing applications .
`25 generate a situation awareness map or other display . The
`Currently a cell phone can determine its geographical
`mobile location component may be moved in the general
`location by using a GPS receiver . The challenges with using
`direction of a first location calculation associated with a first
`a GPS in a handset — is that GPS require significant calcu -
`circular error of probability . After being moved in the
`lations that takes time , up to several minutes ; it is difficult to
`general direction , the mobile location component may coop
`get GPS signals in dense urban areas ; and GPS does not 30 erate with other elements to determine a second location
`distinguish between different elevations at the same loca -
`calculation associated with a second circular error of prob
`tion . Thus , in our shopping area example , GPS would not
`ability . Second and subsequent location calculations are of
`distinguish between entering a large department store from
`increasing precision , enabling an emergency vehicle or
`entering a shopping center plaza in a floor below or entering
`attendant to zero in on a cellular telephone . ”
`U . S . Pat . No . 6 , 972 , 717 — Method And Apparatus For
`a professional service office in a floor above .
`A - GPS ( Assisted - GPS ) , which is intended to reduce the
`Enhanced 911 Location Using Power Control In A Wireless
`time it takes to determine a location as well as possibly
`System — “ A method of locating a mobile telephone includes
`calculate the location in the network in order to reduce the
`steps of receiving , transmitting , increasing and determining .
`complexity required from the cell phone , once again requires
`In the receiving step , a first base station receives a call from
`40 a mobile telephone , the call including a dialed number and
`the network .
`Using Cell - ID by the cell phone is limited as a cell area
`a TDMA signal . In the transmitting step , the base station
`location resolution is not good enough for most location
`transmits a control message to the mobile telephone when
`based applications . On the ubiquitous computing side , divi -
`the dialed number meets a predetermined criterion , such as
`sion of large areas into micro - cells presents a substantially
`being 911 . The control message instructs the mobile tele
`45 phone to transmit the TDMA signal at a maximum power . In
`similar location accuracy threshold .
`There are , of course , numerous patents that have contrib -
`the increasing step , the mobile telephone increases the
`uted to progress in this art — especially in the field of cellular
`TDMA signal to maximum power in response to the control
`telephones — most especially since there is an ongoing
`message . Then in the determining step , location information
`attempt to reach compliance with regulations calling for
`for the mobile telephone is determined based on at least one
`instant automatic location reporting for cellular telephone 50 characteristic of the TDMA signal received at at - least one of
`users requesting emergency services ( police , ambulance , fire
`the first base station and other base stations . In an alternate
`department , etc . ) .
`embodiment , the method is practiced in a mobile telephone
`U . S . Pat . No . 7 , 057 , 556 — Method And Apparatus For
`and the power level is automatically increased in response to
`Geolocating A Wireless Communications Device — “ The
`the dialed number meeting a predetermined criterion . "
`time difference of arrival for a signal received at two or more 55
`U . S . Pat . No . 6 , 674 , 403 — Position Detection And Loca
`receiving sites as transmitted from a wireless communica
`t ion Tracking In
`A Wireless Network — “ A system
`and
`tions device , is determined by a frequency domain tech
`method for performing real - time position detection and
`nique . The constituent frequencies of the signals received at
`motion tracking of mobile communications devices moving
`the two or more receiving sites are determined , including the
`about in a defined space comprised of a plurality of locales
`phase , or a value representative of the phase , of each 60 is provided . A plurality of access points are disposed about
`frequency component . The phase values for the same fre -
`the space to provide an interface between mobile devices
`quency are subtracted to yield a phase difference values as
`and a network having functionality and data available or
`a function of frequency . The slope of the function represents
`accessible there - from . Knowledge of adjacency of locales
`the time difference of arrival for the wireless communica -
`may be used to better determine the location of the mobile
`tions device signal as received at the two receiving sites . To 65 device as it transitions between locales and feedback may be
`determine the mobile location based on the determined time
`provided to monitor the status and configuration of the
`difference of arrival values , a seed or initial location is first
`access points . "
`
`35
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`US 10 , 341 , 811 B2
`
`with the at least one device wherein the stations are sub
`EP 1241909 — Method And Computer Readable Medium
`stantially continuously operating , and the method is com
`For A Program For Location Determination Of A Mobile
`prising the steps of :
`Terminal — “ A method for location determination of a
`( A ) Registering a selected location by first - causing a
`mobile terminal by means of radio connections which are
`controlled by a common server , characterized by providing 5 portable RF communications device at the selected location
`a least one pair of different radio zones closely spaced from
`( i ) to receive an RF communications signal from a plurality
`each other so that distinct directional information trans -
`of local fixed - location service - area antenna stations , and ( ii )
`versely to a boundary between the pair of radio zones is
`to measure reception signal strength respectively associated
`provided upon recording of the movement of the mobile
`with the received signal from at least two of the plurality of
`terminal in the zones . Furthermore , preferably characterized 10 antenna stations ;
`in that a pair of radio zones comprises a first zone and a
`( B ) Recording the selected location by electronically
`second zone , and that information is stored in the server
`storing at least two of the respective reception signal
`defining that the mobile unit is present on one side of said
`strength measurements ;
`boundary if the mobile unit is first recorded in the second
`( C ) Monitoring by second - causing a portable RF com
`zone and then in the first zone , and defining that the mobile 15 munications device ( i ) to receive communications signals
`unit is present on the other side of said boundary if the
`from a plurality of respectively local fixed - location service
`mobile unit is first recorded in the first zone and then in the
`area antenna stations , and ( ii ) to measure reception signal
`strength associated with the signals , and
`second zone . "
`( D ) Determining if the portable RF communications
`The challenges , therefore , are to develop a location
`determining method that would : ( A ) Take place on the cell 20 device of the Monitoring step is at the selected location of
`phone for the benefit of privacy ( monitoring of user location
`the registering step by electronically comparing measure
`by the cell phone and not by the cellular network ) as well as
`ments in the monitoring step with the stored at least two
`in order to reduce the infrastructure required by the cellular
`measurements of the Recording step .
`network to determine cell phone locations ; ( B ) Will not
`According to a simpler categorization , the instant inven
`require heavy calculations by the cell phone in order to be 25 tion relates to a methodological embodiment ( see FIG . 1 )
`able to determine a location fast and with minimal resources
`whereby at least one portable RF communications device in
`so the method be suitable for cheap handsets and not only
`conjunction with at least two fixed - location service - area
`? / ? ? / ?
`/ ? / ?ti?m? / ?? / ?? / ?? / ?? – ? – ?????ti???ti?ti???? – ? – ????
`antenna stations respectively capable of RF communication
`culations ; and ( C ) Provide accurate enough location deter -
`with the at least one device perform the steps of : - 100 - ( I )
`30 using a portable device at a selected location to measure RF
`mination .
`Simply stated , there is a need for performing geographical
`communications signals from the plurality of local fixed
`location determinations with ordinary RF communications
`location service - area antenna stations and electronically
`hardware ( without GPS capability ) because that is less
`storing at least two of the respective reception signal
`expensive than performing the same determination with
`strength measurements ; and - 110 - ( 11 ) Monitoring a portable
`GPS hardware components . Furthermore , there is another 35 device location by causing the device to measure reception
`independent need to perform location determinations within
`signal strength associated with local fixed - location service
`a scope of privacy to the user - in order for him to permit
`area antenna stations signals , and to electronically compare
`application events that depend on location . There is also a
`these measurements with the stored at least two measure
`need for location determination in locations where GPS
`ments .
`reception is problematic . In addition , there is a need for 40
`Please note , the present invention is herein described with
`determining elevation components of location without the
`a certain degree of particularity , however those versed in the
`addition of additional hardware _ especially for devices that
`art will readily appreciate that various modifications and
`are already GPS capable . Likewise , for both cellular tele
`alterations may be carried out without departing from either
`phony and the ubiquitous computing arts there is a need to
`the spirit or scope , as hereinafter claimed . For example , the
`provide elevation location data and / or to reduce infrastruc - 45 majority of the description relates to direct measurements of
`ture intensive application for location determination , prog
`signal strengths and direct comparisons of those measure
`og
`ress in
`at least one of these areas would constitute a
`ments . Such direct measurements are generally correct in a
`meaningful contribution to alleviating a longstanding need
`cellular telephone GSM environment , however in a cellular
`in the art ; and would set the stage for the progress of further
`telephone CDMA environment it is the relative signal
`location - knowledge - dependent applications .
`50 strengths that form an important metric for comparative
`purposes . Similarly , for other antenna space environments ,
`DISCLOSURE OF INVENTION
`measurements and comparisons thereof should conform to
`the underlying policy that governs the management of
`The aforesaid longstanding needs are
`significantly
`antenna space signal strength management , or of equiva
`addressed by embodiments of the present invention , which 55 lent antenna space transmission metric characteristics . For
`specifically relates to a Signal - Comparison Based Location
`example , a strongest signal may be used as a unit to help
`Determining Method . The instant method is especially use -
`normalize other simultaneous measurements ; however ,
`ful in telecommunications and / or ubiquitous computing
`since that strongest signal may encounter inoperative events
`applications wherein there exists a need to provide improved
`or radical environmental changes ( e . g . construction of a
`privacy , and / or to provide elevation location data , and / or to
`60 signal blocking structure between the “ strong ” antenna and
`reduce infrastructure intensive application for location deter -
`the reception location ) , one would prefer to retain a capa
`mination .
`bility to renormalize measurements within the context of the
`The instant invention relates to embodiments of a Signal
`instant method .
`Comparison Based Location - Determining Method , operable
`Simply stated , a conceptually instant enabling embodi
`by at least one portable RF communications device in 65 ment of the present invention is a cellular telephone device
`conjunction with at least two fixed - location service - area
`that looks at the signal strengths ( and preferably correspond
`antenna stations respectively capable of RF communication
`ing local base station service area antenna IDs ) to charac
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`US 10 , 341 , 811 B2
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`distance from the service antenna , it can only logically
`terize an antenna space signal - reception signature as being
`presume that the probability of it also being in that small
`substantially equivalent to a current location . The device
`house is substantially proportional to the fragment of arc that
`needs a means for remembering this signal strength ( pref -
`the house represents with respect to the circumference
`erably with the antennas ' IDs ) , and this means may be on the
`device per se , kept at a remote storage ( or even transferred 5 specified by that radius .
`from the current device to the owner ' s next cell phone ) . The
`OK , now if the owner of the cell - phone is a tractor driver
`device can “ know ” that it has returned to the original
`who typically continuously drives back and forth across the
`location where the signal strengths were measured ( and the
`length and breadth of the service antenna coverage area , then
`antennas ' IDs preferably captured ) . Since the device is
`the presumed probability that the cell - phone radius mea
`capable of receiving and measuring such signals , the device 10 surement corresponds to him being in that house is as
`simply performs such reception measurements and com
`described . However , if he is in that house an average of eight
`pares these measurements with the remembered signal
`hours per day , then there is already a high probability that the
`strength combinations . Whenever there is
`a substantial
`radius measurement from the cell - phone indicates that he is
`equivalence between the remembered signal strengths ( and
`in the house . More likely , the cell - phone owner is not an
`IDs ) and the currently being monitored signal strengths ( and 15 indentured round - the - clock tractor driver , but an ordinary
`IDs ) , then the device can conclude that it is probably at the
`vehicle commuter who goes from that house to various other
`original location where the original measurements were
`locations , using established paved roads . This being the
`performed .
`case , there are perhaps four to six locations where these
`Now , illustrative enabling embodiments of a Signal - Com
`roads coincide with that radius measurement , and it is only
`parison Based Location - Determining Method of the instant 20 of minimal probability that a part of one of those roads
`invention according to a simplified aspect - substantially
`follows that circumference for any span or that the cell
`relate to a method for determining a cell phone ( or a
`phone owner parks his vehicle at such a location . Accord
`ubiquitous computer ) location comprising : ( A ) at a desired
`ingly , there is an already very high probability that the radius
`location Causing a cell phone ( or a ubiquitous computer )
`measurement from the cell - phone indicates that he is in the
`to measure signal strengths from surrounding cells and to 25 house .
`record the signal strengths measured by the cell phone ( or
`One can easily provide a significant increase in this
`the ubiquitous computer ) from the surrounding cells ; ( B ) at
`already very high probability by delaying confirmation of
`a current location Causing a cell phone ( or a ubiquitous
`the measurement calculation — at least until it is performed
`computer ) to measure the signal strengths from surrounding
`at least twice . Specifically , to eliminate spurious observation
`cells ; and ( C ) Causing the Cell phone ( or ubiquitous com - 30 of the cell - phone owner traversing at that circumference , one
`puter ) to compare the measured signal strengths from sur -
`need only wait to see that the same measurement had been
`rounding cells at the current location with the recorded
`made twice with perhaps a 2 - 3 minute interval wait there
`signal strengths from surro