(12) United States Patent
`Fan
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 6,664,922 Bl
`Dec. 16, 2003
`
`I IIIII IIIIIIII Ill lllll lllll lllll lllll lllll lllll lllll lllll 111111111111111111
`US006664922B 1
`
`(54) METHOD FOR DISTRIBUTING LOCATION(cid:173)
`RELEVANT INFORMATION USING A
`NETWORK
`
`(75)
`
`Inventor: Rodric C. Fan, Fremont, CA (US)
`
`(73) Assignee: At Road, Inc., Fremont, CA (US)
`
`( *) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by O days.
`
`(21) Appl. No.: 09/365,671
`
`(22) Filed:
`
`Aug. 2, 1999
`
`5,970,143 A * 10/1999 Schneier et al. .............. 380/23
`6,111,953 A * 8/2000 Walker et al.
`................ 380/51
`6,131,067 A * 10/2000 Girerd et al.
`............... 701/213
`6,154,745 A * 11/2000 Kari et al.
`.................. 707/100
`6,169,515 Bl * 1/2001 Mannings et al.
`....... 342/357.1
`6,175,740 Bl * 1/2001 Souissi et al.
`.............. 455/456
`6,185,198 Bl * 2/2001 LaDue ....................... 370/329
`6,212,475 Bl * 4/2001 France et al. ............... 701/214
`6,249,245 Bl * 6/2001 Watters et al. ......... 342/357.03
`6,269,446 Bl * 7/2001 Schumacher et al. ....... 713/176
`
`* cited by examiner
`
`Primary Examiner-Theodore M. Blum
`(74) Attorney, Agent, or Firm-Edward C. Kwok;
`MacPherson Kwok Chen & Heid LLP
`
`Related U.S. Application Data
`
`(57)
`
`ABSTRACT
`
`( 63) Continuation-in-part of application No. 08/924,042, filed on
`Aug. 28, 1997, now Pat. No. 5,959,577.
`Int. Cl.7 ............................ GOlS 5/02; H04B 7/185
`(51)
`(52) U.S. Cl. ..................................... 342/357.1; 701/213
`(58) Field of Search ......................... 342/357.09, 357.1;
`701/213
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`5,629,981 A * 5/1997 Nerlikar ...................... 380/25
`5,819,199 A
`10/1998 Kawai et al.
`............... 701/200
`5,848,373 A
`12/1998 DeLorme et al. ........... 701/200
`
`A method for distributing locating-relevant information
`includes providing a GPS position of a client to a server on
`a data network, and returning location-relevant information
`by the server based on the specified GPS position. Such
`location-relevant information include travel or tourist infor(cid:173)
`mation ( e.g., locations of tourist attractions, hotels, or
`restaurants). Commercial information such as discount cou(cid:173)
`pons or advertising selected based on the Client's GPS
`position can also be provided. Financial or business trans(cid:173)
`actions can be conducted using the GPS position for authen(cid:173)
`tication or identification.
`
`34 Claims, 9 Drawing Sheets
`
`GPS Satellites
`
`.. o···
`0
`
`I 27
`
`Twitter Exhibit 1021
`Twitter, Inc. v. BlackBerry Ltd.
`Page 00001
`
`

`

`U.S. Patent
`
`Dec. 16, 2003
`
`Sheet 1 of 9
`
`US 6,664,922 Bl
`
`GPS Satellites
`
`8
`
`Wireless
`data path
`
`Data
`processing
`station
`
`.. 0 ...
`
`0
`
`20
`\.
`Service
`provider
`
`Monitor
`unit
`
`I 27
`
`Fig. l
`
`Page 00002
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`

`

`U.S. Patent
`
`Dec. 16, 2003
`
`Sheet 2 of 9
`
`US 6,664,922 Bl
`
`18
`
`r J3\ ___.___
`
`GPS
`correction
`station
`
`" ' - GPS
`. • • . . • . . . . correction
`station
`
`32
`
`Database storage
`
`Area map storage
`
`Position
`table
`
`63
`
`Delta pseudo range table
`
`33
`
`39
`
`27
`
`Fig. 2
`
`Page 00003
`
`

`

`U.S. Patent
`
`Dec. 16, 2003
`
`Sheet 3 of 9
`
`US 6,664,922 Bl
`
`53
`
`Call to
`establish
`link
`
`51
`
`66
`
`Start
`
`68
`
`70
`
`74
`
`Route
`programming
`mode
`
`no
`
`yes
`
`75
`
`78
`
`Verify old
`keyword
`
`Pre-program
`route routine
`
`80
`
`Enter new
`keyword
`
`82
`
`Double chec
`new keyword
`
`Minimum Distance
`
`No
`
`Store new
`keyword
`
`81
`
`Exit
`
`Fig. 3
`
`Page 00004
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`

`

`U.S. Patent
`
`Dec. 16, 2003
`
`Sheet 4 of 9
`
`US 6,664,922 Bl
`
`Data Processing Program Flow
`
`90
`
`122
`
`Input from
`monitor unit
`
`120
`
`100
`
`Receive outbound
`data package
`
`1 1
`
`Position
`update
`
`update
`differential
`correction
`table
`
`123
`
`125
`
`126
`
`Verify
`authentication
`key
`
`Identify image
`re uested
`
`Send requested
`image to
`monitor unit
`
`128
`
`Return
`
`92
`
`94
`
`Database
`search
`command
`
`Search
`database us
`input positio
`and search
`command
`
`96~--'---~
`Return search
`results
`
`98
`
`Return
`
`no
`
`Establish pseudo range
`table
`
`cu ate correcte position
`using correction table and
`pseudo range table
`
`108
`
`110
`
`Update
`position table
`
`Link multiple
`mobile units of one
`group (One company)
`
`111
`
`112
`
`115
`
`Overlay on map
`image to create
`mobile unit map
`
`Replace old unit
`map
`
`118
`
`Return
`
`Fig. 4
`
`Page 00005
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`

`

`U.S. Patent
`
`Dec. 16, 2003
`
`Sheet 5 of 9
`
`US 6,664,922 Bl
`
`18"'
`
`140
`
`144
`
`GPS
`antenna
`
`Input
`device
`
`142
`
`Display
`device
`
`':. ......
`
`GPS receiving
`J..W"---------1 Micro-
`circuit
`processor1--~~++1
`L....:.=..:.~--.-----'
`
`135
`
`146
`
`Wireless
`modem circuit
`
`132
`
`131
`
`"" ...... .
`
`Wireless
`phone
`
`Memory
`device
`
`Fig. 5
`
`Network
`connection
`
`Data router
`
`Data processing
`Computer
`
`Memory storage
`block
`
`Fig. 6
`
`150
`
`152
`
`155
`
`Page 00006
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`

`

`U.S. Patent
`
`Dec. 16, 2003
`
`Sheet 6 of 9
`
`US 6,664,922 Bl
`
`160
`
`162
`
`165
`
`168
`
`170
`
`ID
`xx
`**
`
`XXX
`*
`*
`
`Latitude Longitude Ve ocity
`xxxx
`xxxx
`**
`**
`**
`**
`
`XXX
`*
`*
`
`Fig. 7
`
`172
`~
`ID
`
`175
`\
`
`PRl, PR2, PR3, PR4, PRS, PR6, PR7, PR8 Time _;;o
`
`178
`\
`
`MUI
`
`· X X X X X X X X
`
`1 :00.00
`
`MUI
`
`X X X X
`
`X X
`
`1:00.lC
`'
`
`Fig. 8
`
`180
`
`186
`
`39
`
`I
`
`188
`
`Area DPRl, DPR2, DPR3, DPR4, DPR5, DPR6, DPR7, DPR8 Time
`
`A
`
`A
`
`A
`
`X
`X
`X X
`X
`
`X
`
`X
`
`X
`
`X
`
`X
`
`X
`
`X
`
`X
`
`X
`
`X
`
`X
`
`X
`
`1 :00.00
`
`1:00.10
`
`1:00.50
`
`Fig. 9
`
`Page 00007
`
`

`

`U.S. Patent
`
`Dec. 16, 2003
`
`Sheet 7 of 9
`
`US 6,664,922 Bl
`
`190
`
`192
`
`Input received
`pseudo range
`
`Time match
`
`Corrected pseudo range
`= received PR +
`delta pseudo range
`
`Apply pseudo ranges to
`navigational solution
`
`198
`
`191
`
`Output
`Distance
`
`corrected position
`.-----------,
`Corrected position
`OU ut
`
`200
`
`Fig. 10
`
`202
`
`Master
`key
`
`205
`
`Fig. 11
`
`Page 00008
`
`

`

`U.S. Patent
`
`Dec. 16, 2003
`
`Sheet 8 of 9
`
`US 6,664,922 Bl
`
`212
`
`208
`
`Food
`
`Jl 6
`Hotel<]_/
`
`Traffic
`
`On/Off
`
`Scroll
`
`211
`
`213
`
`Fig. 12
`
`1
`
`~
`
`..,,,.--- 1
`
`220
`
`On/Off
`
`(D Scroll
`
`Enter
`
`Fig. 13.
`
`Page 00009
`
`

`

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`N
`N
`\0
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`a-..
`a-..
`_,.a-..
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`e
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`'Jl =(cid:173)~
`
`8
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`ri
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`~
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`I 4-·
`
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`
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`
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`Internet
`
`..
`...
`
`..
`... Gateway
`Network
`
`(
`
`'
`
`l
`
`~
`
`.....
`
`Field Client
`
`Wireless Modem
`GPS receiver
`
`'
`I U O \
`
`'
`
`Page 00010
`
`

`

`BACKGROUND OF THE INVENTION
`1. Field of Invention
`This invention relates to a method for distributing
`location-relevant information to a mobile client based upon
`the position of the client.
`2. Description of the Related Art
`The global position system ("GPS") is used for obtaining
`position information. A GPS receiver receives ranging sig(cid:173)
`nals from several GPS satellites, and triangulates these
`received ranging signals to obtain the measured position of
`the receiver. A more detailed discussion of a GPS receiver is
`found in U.S. patent application ("CopendingApplication"),
`Ser. No. 08/779,698, entitled "Structure of An Efficient
`Global Positioning System Receiver," assigned to the
`present assignee. The Copending Application is hereby
`incorporated by reference.
`One application of GPS is vehicle location. The Parent
`Application provides a method for vehicle location using
`both the GPS system and a data network, such as the
`Internet. Commercial activities have become an important
`part of the Internet. Users of the Internet can access infor- 35
`mation anywhere in the world with equal ease. However,
`because of the global nature of the Internet, the user of
`information obtained from the Internet filters out a large
`amount of that information to get to relevant information of
`local interest.
`
`25
`
`30
`
`US 6,664,922 Bl
`
`1
`METHOD FOR DISTRIBUTING LOCATION(cid:173)
`RELEVANT INFORMATION USING A
`NETWORK
`
`CROSS REFERENCE TO RELATED
`APPLICATION
`This Application is a continuation-in-part application of
`U.S. patent application (the "patent application" Ser. No.
`08/924,042, filed Aug. 28, 1997 now U.S. Pat. No. 5,959,
`577, entitled "Method and Structure for Distribution of
`Travel Information Using Network," now U.S. Pat. No.
`5,959,577 which is assigned to @Road Corporation, which
`is also the Assignee of the present application.
`
`2
`According to another aspect of the present invention, a
`method is provided for conducting a business or financial
`transaction over a data network. The method includes (a) by
`a first party, attaching a GPS position of the first party to a
`5 digital instrument transmitted over the data network; and (b)
`by a second party, accepting the digital instrument to com(cid:173)
`plete the transaction. The GPS position can be attached as a
`code word formed using the GPS position or embedding the
`GPS position. To ensure security, such a code word can be
`10 formed using an encryption process. Under such a method,
`the second party can use the GPS position received from the
`first party to authenticate the digital instrument, or to iden(cid:173)
`tify the first party first party, or to establish the location at
`which said transaction is deemed to have taken place, for
`15 legal and other purposes. Thus, the present invention allows
`a simple and efficient authentication, identification or sig(cid:173)
`nature scheme for business to be conducted on the Internet.
`The present invention is better understood upon consid(cid:173)
`eration of the detailed description below and the accompa-
`20 nying drawings.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 illustrates a vehicle locating system which includes
`a data network 27.
`FIG. 2 illustrates a data processing station 18 in a vehicle
`location system.
`FIG. 3 illustrates a program flow in a mobile unit.
`FIG. 4 illustrates a program flow in a data processing unit.
`FIG. 5 is a block diagram of a mobile unit.
`FIG. 6 is a block diagram of a data processing unit.
`FIG. 7 represents one implementation of position table 33.
`FIG. 8 illustrates a pseudo-range table 40 for indicating
`the pseudo-ranges of a mobile unit over a period of time.
`FIG. 9 represents one implementation of delta-pseudo(cid:173)
`range table 39, containing delta-pseudo-ranges obtained
`from various service areas.
`FIG. 10 illustrates the logic flow of a differential correc-
`40 tion process.
`FIG. 11 illustrates a process for generating a time-limited
`key from a master key and a specified duration.
`FIG. 12 illustrates one display in a mobile unit.
`FIG. 13 illustrates one display in a mobile unit, specifi(cid:173)
`cally displaying a map with travel information overlaid
`thereon.
`FIG. 14 shows a model of distributing location relevant
`information to a mobile unit according to one embodiment
`of the present invention.
`
`SUMMARY OF THE INVENTION
`The present invention provides methods applicable to
`commercial activities between a mobile unit with a wireless
`link with a server on a data network, such as the Internet. 45
`According to one aspect of the present invention, a method
`is provided for distributing location-relevant information
`over a data network to a client includes: (a) providing a GPS
`position of the client to a server over the data network; (b)
`obtaining at the server the location-relevant information 50
`using the GPS position provided by the server; and (c)
`returning to the client the location-relevant information. In
`one embodiment, the client communicates over a wireless
`link with a gateway of the data network, which then acts as
`a proxy client for accessing the server. Under this method, 55
`the GPS position can be provided to the server by the client
`in conjunction with a query for information. Based on the
`supplied GPS position, the server can then select to return
`only that information relevant to the client from the non(cid:173)
`location specific information responsive to the query, 60
`thereby relieving the client of the task of filtering for
`relevant information. In one implementation, the client uses
`an Internet browser application program. Location-relevant
`information includes advertising of local interest to said
`client, discount coupons accepted by businesses in the local 65
`vicinity of said client, and addresses of local points of
`interest.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`FIG. 1 illustrates a system of the present invention which
`includes a data network. As shown in FIG. 1, a vehicle
`locating system according to the present invention includes:
`GPS satellite constellation 8, data network 27 with nodes 5,
`10, 12 and 15, data processing station 18, monitor unit 22,
`and mobile units 1 and 3. Mobile unit 1 is a portable (e.g.,
`handheld) device while mobile unit 3 is installed in a
`vehicle. Mobile units 1 and 3 each include a GPS receiver,
`a transmitter for transmitting messages to data network 27,
`and a microprocessor. Each mobile unit can also be provided
`a data receiver for receiving messages from the data net(cid:173)
`work. Mobile units may fall into different groups, each of
`which requires a different handling procedure. For example,
`moving companies can be grouped separately from taxi
`
`Page 00011
`
`

`

`US 6,664,922 Bl
`
`4
`3
`companies for management convenience. Monitor units
`pseudo-ranges received from satellite constellation 8 to
`perform system-wide or regional control and data-gathering
`provide a corrected measured position of the mobile unit.
`functions. The following description uses mobile unit 1 as an
`The corrected measured position is then stored in position
`table 33 (FIG. 2).
`example of the mobile units of the present invention.
`The mobile unit of the present invention allows a user to 5
`A differential correction station receives code sequences
`from GPS satellite constellation 8 (FIG. 1) to obtain a first
`report its position and to obtain travel-related information
`over a data network. Travel-related information includes
`set of pseudo-ranges based on the received code sequences.
`The differential correction station then calculates a second
`information such as directions to a destination ( e.g., a gas
`set of pseudo-ranges based on its known position and the
`station, a hotel, or a restaurant), or traffic conditions in the
`10 relative positions of the satellites in satellite constellation 8.
`immediate vicinities of concern. For example, using a GPS
`Delta-pseudo-ranges are then computed using the two sets of
`receiver, mobile unit 1 receives a positioning signal that
`pseudo-ranges. These delta-pseudo-ranges are provided to
`contains code sequences from GPS satellite constellation 8
`data processing unit 38, and stored in delta-pseudo-range
`and converts the code sequences into pseudo-range infor(cid:173)
`table 39 for computing corrected measured positions of the
`mation. When the operator of the mobile unit wishes to
`15 mobile units. Alternatively, correction to the measured posi(cid:173)
`request travel-related information, a query is sent in an
`tion can also be achieved using positional corrections, rather
`outbound data package, which includes the operator's query,
`than delta-pseudo-ranges. To obtain a positional correction,
`the pseudo-ranges and a time-stamp indicating the time the
`a differential correction station receives GPS positioning
`pseudo-ranges were obtained. (In this detailed description,
`code sequences, and obtains, based on the received code
`an outbound data package refers to a data package trans(cid:173)
`20 sequences, a measured position of its own position
`mitted from a mobile unit.) A history showing the most
`expressed in terms of the longitude and latitude. This
`recent positions of mobile unit 1 may also be included in the
`measured position ( called a "fix") is compared to the pre(cid:173)
`outbound data package. In this embodiment, data processing
`cisely known position of the differential correction station to
`station 18 keeps track of the time since the last update. The
`obtain the positional correction expressed in a delta-
`outbound data package is then transmitted by mobile unit l's
`25 longitude quantity and a delta-latitude quantity. To use these
`transmitter over wireless link 23 to a service connection 10
`delta-longitude and delta-latitude quantities to find a cor(cid:173)
`on data network 27, which relays the outbound data package
`rected measured position of mobile unit 1, the pseudo-range
`to data processing station 18. Alternatively, instead of send(cid:173)
`obtained by mobile unit 1 is first used to triangulate a
`ing pseudo-ranges as described above, mobile unit 1 obtains
`measured position to obtain a raw position expressed in a
`a "measured" position by applying a triangulation technique
`30 raw longitude and a raw latitude. The corrected longitude for
`on the pseudo-ranges. This measured position of mobile unit
`the mobile unit is this raw longitude plus the applicable
`1 is then included in an outbound data package. The out(cid:173)
`delta-longitude obtained by the differential correction sta(cid:173)
`bound data package also includes a position update request
`tion in the vicinity. Likewise, the corrected latitude is the
`or query, together with the pseudo-ranges or the measured
`raw latitude of the mobile unit plus the delta-latitude com-
`position. Mobile unit 1 reports its position either
`35 puted by the differential correction station in the vicinity.
`automatically, according to a predetermined schedule, or
`upon a command manually entered by an operator into the
`In addition to computing the corrected measured position,
`mobile unit. Wireless communication between mobile unit 1
`data processing station 18 searches a database 32 and
`associated area map storage 63 to process the operator's
`and data network 27 can be accomplished, for example,
`query received in the outbound data package. Database 32
`using a cellular digital packet data (CDPD) modem or via
`40 maintains such travel-related information as maps, traffic
`satellite.
`situation in a particular area, positions of service stations and
`FIG. 2 illustrates data processing station 18 of the present
`destinations of interest. Storage for database 32 can be
`invention, including data process unit 38 which handles
`implemented using any mass storage media, such as hard
`computation at data processing station 18. If data processing
`disks, RAMs, ROMS, CD-ROMS and magnetic tapes. For
`station 18 receives an outbound data package that includes
`45 example, infrequently updated information (e.g., maps or
`a measured position of the mobile unit (presumably the
`destinations of interest) can be stored on CD-ROMs, while
`position of the vehicle), the measured position is entered into
`frequently updated information (e.g., current traffic
`a position table 33 (FIG. 2). If the outbound data package
`conditions) can be stored on RAM. Data processing unit 38
`includes pseudo-ranges, however, data processing station 18
`accesses database 32.
`obtains the measured position of the mobile unit for position
`Position table 33 stores the last known measured positions
`table 33 by applying a triangulation technique on the 50
`pseudo-ranges.
`of the mobile units in the system. The measured position
`stored in position table 33 can be used for compiling vehicle
`Alternatively, data processing station 18 can also use
`position maps by monitor unit 22 (FIG. 1). FIG. 7 represents
`pseudo-ranges in conjunction with differential correction
`one implementation of position table 33. Position table 33
`information, or delta-pseudo-ranges. The delta-pseudo(cid:173)
`contains the measured position of several mobile units,
`ranges, which are obtained by data processing unit 38 from 55
`identified respectively by an identification number 160, at
`correction stations ( e.g., correction stations 37) and stored in
`particular times 162. The measured position of each mobile
`a delta-pseudo-range table (e.g., delta-pseudo-range table 39
`unit is represented by time-stamp 162, a measured latitude
`of FIG. 2), are correction factors for the geographical area in
`value 165, a measured longitude value 168, and a velocity
`which the mobile unit is currently located. Data processing
`170.
`unit 38 can connect to correction stations 37 via wired or 60
`Delta-pseudo-range table 39 stores the delta-pseudo(cid:173)
`wireless communication links, or via a data network, such as
`ranges of each service area. FIG. 9 represents one imple(cid:173)
`data network 27. The position of a differential correction
`mentation of delta-pseudo-range table 39 used by data
`station is precisely known. Typically, a differential correc(cid:173)
`processing station 18 (FIG. 1). As shown in FIG. 9, delta-
`tion station serves an area 200 miles in diameter. In the
`present embodiment, a differential correction station in each 65 pseudo-range table 39 maintains the delta-pseudo-ranges
`of the vehicle locating service's service areas is desired. The
`186 of each service area (indicated by identification 180)
`from each of a group of satellites at each of specified times
`delta-pseudo-ranges are used in conjunction with the
`
`Page 00012
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`

`US 6,664,922 Bl
`
`6
`5
`188. Each value of the delta-pseudo-range data 186 indicate
`In the embodiment shown in FIG. 1, another set of
`terminals (e.g., monitor unit 22) are provided in some
`the delta-pseudo-range to a particular satellite. Area map
`storage 63 stores area maps with position markers indicating
`applications to monitor the activities of the mobile units. For
`the mobile units and landmarks. The response to the query
`example, a monitor unit may send a request to data process(cid:173)
`can be in text, graphical or audio form. If the query is for 5
`ing station 18 to obtain the measured position and speed of
`a specified mobile unit. This capability can be used, for
`directions, for example, a map including the measured
`example, by a trucking company to track the positions of its
`position or corrected measured position and the position of
`fleet of trucks for scheduling and maintenance purposes.
`the destination is retrieved. Typically, a position marker is
`Monitor unit 22 can be a fixed unit or a portable unit. A
`provided to identify the position of the requested destina(cid:173)
`portable monitor unit 22 is equipped with a wireless trans(cid:173)
`tion. The map and a result of the database search (i.e., a 10
`ceiver for accessing data network 27 via service provider 20
`response to the operator's query), are then packaged into an
`or wireless network service connection 10. Monitor unit 22
`inbound data package, which is transmitted to mobile unit 1
`may also communicate with mobile unit 1 through data
`through data network 27 via network connection 10 and
`network 27 using a message exchange protocol. For
`wireless link 23. (In this detailed description, an inbound
`example, monitor unit 22 may send a special command to
`data package refers to a data package received by a mobile 15
`mobile unit 1, and mobile unit 1 may send a message
`unit or a monitor unit.)
`addressed to monitor unit 22. In one example the message
`Instead of computing the corrected measured position at
`communicated between mobile unit 1 and monitor unit 22 is
`data processing station 18, a microprocessor in mobile unit
`in the form of an electronic mail message. Of course,
`1 can also be used to compute a corrected measured position
`communication between monitor unit 22 and mobile unit 1
`from pseudo-range information the mobile unit received 20
`can be encrypted for security purpose or to prevent unau(cid:173)
`from satellite constellation 8 and delta-pseudo-range infor(cid:173)
`thorized use. Monitor unit 22 also displays the elapsed time
`mation received from data processing station 18. Under this
`since last position update graphically ( data collected by data
`arrangement, instead of the measured corrected position,
`processing unit). The elapsed time can be represented
`data processing station 18 includes in the inbound data
`graphically as a color code, grades of shade, a flashing
`package the delta-pseudo-ranges for the current position of 25
`interval, or any suitable symbolic representation.
`mobile unit 1. In any event, upon receiving the inbound data
`When the Internet is used as data network 27, data
`package, mobile unit 1 displays on its screen the corrected
`processing station 18 is a node on the Internet and is
`measured position and the position of the destination, typi(cid:173)
`assigned an Internet address. Monitor unit 22 can include a
`cally by overlaying the positions on the map received, along
`computer installed with a conventional web browser. The
`with the response to the query. For example, if the operator 30
`Internet address of data processing station 18 is used by the
`requests directions to a nearby gas station, a position marker
`monitor unit for communicating with data processing unit
`identifying the gas station and a position marker identifying
`18.
`the mobile unit's current position are displayed on the map,
`together with the response to query (i.e., directions as to how
`A land-based vehicle normally travels only a relatively
`to get to the gas station.) The response to the query can be 35
`limited distance during a short time period. On the other
`a text description or a graphical representation of the direc(cid:173)
`hand, an area map showing the location of the vehicle is only
`tions placed next to or overlaying the map. Alternatively,
`useful when the vicinity of the vehicle is also shown.
`instead of sending the map, the positions and the response to
`Consequently, a vehicle is often located in the area covered
`by the same map over a time period of several position
`query in the inbound data package, data processing station
`18 can provide in the inbound data package a picture file of 40
`updates. This principle can be utilized to reduce the amount
`the map, with the markers and the response to the query
`of data transmitted and thus improve the efficiency of the
`already embedded. Special markers can be used for indicat(cid:173)
`system. For example, a plugin program for a web browser
`can be installed in monitor unit 22. During each location
`ing conditions of interest. For example, a mobile unit that
`has been stationary for a predetermined period of time can
`update, the plugin program downloads the new location of
`be marked by a special marker to signal monitor units of an 45
`the vehicle and compares the new location with an area map
`stored in monitor unit 22. If the new location of the vehicle
`exceptional condition. The picture file is then simply dis(cid:173)
`played by mobile unit 1.
`is within the boundary of the area map, a new location
`marker representing the vehicle is overlaid on the area map.
`Data network 27 can be a wide area data network, such as
`If the location of the vehicle is outside the boundary of the
`the Internet, or a telephone network, including wired or
`wireless communications, or both. Data network 27 can also 50 area map, a new area map is downloaded and the location of
`the vehicle is marked on the new area map. The plugin
`be accessed via a satellite link. For example, in FIG. 1,
`program can be downloaded over the Internet from the
`satellite 5 provides access to data network 27, communicat(cid:173)
`vehicle location service provider, or can be loaded directly
`ing with mobile unit 3 through a wireless communication
`from software storage media.
`channel 25. Satellite 5 allows the present invention to be
`FIGS. 12 and 13 shows one implementation of mobile
`used in a remote area where other forms of 55
`unit 1 adapted for allowing an operator to send a travel(cid:173)
`telecommunication, such as a cellular phone system, are
`related query. As shown in FIG. 12, mobile unit 1 includes
`expensive to implement. In one embodiment, the inbound
`liquid crystal display (LCD) 212, transceiver/antenna
`and outbound data packages are encrypted for security. One
`assembly 208, power switch 211, a scroll key 213, and an
`method of image encryption and decryption that can be used
`60 "enter" key 215. Scroll key 213 and enter key 215, in
`for this application is described in U.S. Pat. No. 5,541,993
`conjunction with a software-generated command menu 210
`by Eric Fan and Carey B. Fan, July 1996. This disclosure of
`displayed on LCD 212, allow the user to enter simple
`U.S. Pat. No. 5,541,993 is hereby incorporated herein by
`reference. Service connection 10 can be a commercial
`commands, such as the travel-related query described above.
`For example, as shown in FIG. 12, command menu 210
`transceiver station such as a cellular phone transceiver
`65 shows selections "gas station", "food", "hotel", and "traffic".
`station. In another embodiment, service connection 10 is a
`By pressing scroll key 213, an operator of mobile unit 1
`dedicated transceiver station for handling communication
`causes a cursor 216 to step through the selections. When the
`related to the present invention.
`
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`US 6,664,922 Bl
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`7
`operator presses enter key 215, an outbound data package
`including the query or command is transmitted by
`transceiver/antenna assembly 208 to processing station 18.
`In this embodiment, as shown in FIG. 13, the response from
`data station 18 is received in mobile unit 1 through 5
`transceiver/antenna assembly 208 and displayed on LCD
`212. In this instance, the query sent to data station 18
`corresponds to the selection "gas station". In FIG. 13, data
`processing station 18 returns to mobile unit 1, in an inbound
`data package, a map which is displayed on LCD 212, 10
`showing the vicinity of mobile unit 1. Mobil unit l's
`position is indicated on LCD 212 by a marker 225. The
`locations of several gas stations, indicated by markers 220
`are also displayed.
`FIG. 3 is a flow diagram showing the operation of mobile
`unit 1 (FIG. 1). At step 51, one of four modes of operation
`is selected: periodic update mode 53, route diversion trig(cid:173)
`gered mode 62, passive update mode 68, minimum distance
`mode 66 and service mode 70. Under periodic update mode
`53, mobile unit 1 periodically reports pseudo-ranges of its
`position to data processing station 18, so as to update the
`measured position of mobile unit 1 stored at data station 18.
`Under route diversion triggered mode 62, mobile unit 1
`reports its position only upon a diversion from a pre(cid:173)
`programmed route or a diversion from a predetermined time
`schedule. Under update mode 68, the position of mobile unit
`1 is reported under an operator's control. Service mode 70
`is not an operating mode, but is used to program mobile unit
`1.
`
`Under periodic update mode 53, at step 55, mobile unit 1
`waits for the next scheduled position update. At the time of
`a scheduled update, i.e., at step 58, mobile unit 1 calls to
`establish network service connection 10 for accessing data
`network 27, and transmits to data processing station 18 an
`outbound data package. Upon receiving the outbound data
`package, data processing station 18 responds to the opera(cid:173)
`tor's query by searching database 32, updating a map
`retrieved from map storage 63, and transmitting the map to
`mobile unit 1 an inbound data package.
`Under route diversion triggered mode 62, the measured
`position of mobile unit 1 is obtained at the mobile unit using
`pseudo-range data without differential correction. At step 65,
`this measured position is compared with a pre-programmed
`route and a schedule. If the current position is a substantial
`deviation from the pre-programmed route or from the
`schedule, mobile unit 1 branches to step 55 to create a
`service connection 10 for performing the update described
`above at the next scheduled reporting time.
`Under passive update mode 68, a measured position
`update occurs when an operator issues an update request in
`an outbound data package. At step 69, when an operator
`initiates an update request , mobile unit 1 branches to step
`58 to create network service connection 10. An outbound
`data package including the update request is transmitted via 55
`network service connection 10 to data processing station 18
`over data network 27.
`Under minimum distance mode 66, when the distance
`traveled since the last update exceeds a threshold value, a
`new update is issued. Step 67 compares the distance traveled
`since the last update with the threshold value.
`Under service mode 70, an operator of mobile unit 1 can
`effectuate two major functions: route programming function
`74 and password update function 72. In route programming
`function 74, the operator of mobile unit 1 enters a new r