as United States
`a2) Patent Application Publication co) Pub. No.: US 2002/0145561 A1
`(43) Pub. Date: Oct. 10, 2002
`
`Sandhuetal.
`
`US 20020145561A1
`
`(54) METHOD AND SYSTEM FOR A PLURALITY
`OF MOBILE UNITS TO LOCATE ONE
`ANOTHER
`
`(76)
`
`Inventors: Kulbir S. Sandhu, Fremont, CA (US);
`Roderic C. Fan, Fremont, CA (US);
`David Mleczko, San Jose, CA (US);
`Kenny Nguyen, Mountain View, CA
`(US); Carey Fan, Fremont, CA (US)
`
`Correspondence Address:
`SKJERVEN MORRILL LLP
`25 METRO DRIVE
`SUITE 700
`SAN JOSE, CA 95110 (US)
`
`(21) Appl. No.:
`
`09/829,645
`
`(22)
`
`Filed:
`
`Apr. 9, 2001
`
`Publication Classification
`
`Tint, C7eeeceecceseneeeeceennsneneeennne GOI1S 5/14
`(SV)
`(52) US. CI. ieee sees cessesseessnsseneseseesneeness 342/357.09
`
`(57)
`
`ABSTRACT
`
`A method and system whereby two mobile units can locate
`each otheris presented. A user connects an interface device,
`such as a personal digital assistance (PDA), a wirclcss
`phone,a laptop, or a pager, to a mobile unit. The mobile unit
`regularly obtains its location through a location-determining
`technology (e.g., GPS) and sends the location to a service
`provider computer. The service provider computer maintains
`a database of the current location of all the mobile units, and
`provides the location of mobile units to each of the mobile
`units. The mobile unit communicates with the service pro-
`vider wirelessly through a communication network and a
`data network, for example the Internet.
`
`Auser of the mobile unit can send messages to other users
`with a location stamp, which indicates the location of the
`message sender’s mobile unit. In addition, a user can send a
`request to be notified when a target mobile unit reaches a
`reference point. The reference point may be defined relative
`to the location of the requester. Alternatively, the reference
`point may be an address or a landmark. Uponreceiving the
`request, the service provider computer tracks the distance
`between the target mobile unit and the reference point, and
`sends a notification to the requester when the target mobile
`unit reaches the reference point.
`
`_10-i
`
`GPS Receiver
`
`Wireless Modem
`
`Processor
`
`Memory
`Pretiminary tocation cata
`
`,
`
`correction factors
`
`Google Exhibit 1016
`Google Exhibit 1016
`Google v. Mullen
`Google v. Mullen
`
`

`

`US 2002/0
`5
`
`145561 Al
`
`Patent Application Publication Oct. 10,2002 Sheet 1 of 5
`
`
`
`FIG, |
`
`104
`
`Wireless Modem
`
`Processor
`
`Memory
`____Prelmunary location cata
`correction factors
`
`FIG. 2
`
`

`

`Patent Application Publication Oct. 10,2002 Sheet 2 of 5
`
`US 2002/0145561 Al
`
`subscribe for service
`
`obtain mobile unit
`
`
`
`submit device ID and/or iP address
`
`=
`
`30
`
`3|
`
`22.
`
`receive login name and password
`
`34
`
`set up or changeuserprofile
`
`3L
`
` modify
`
`38
`
`profile?
`
`
`
`send request or announcement
`
`|
`
`™
`
`FIG. 3
`
`

`

`Patent Application Publication Oct. 10,2002 Sheet 3 of 5
`
`US 2002/0145561 Al
`
`Aa
`
`User Profile Database
`
`
`Map Storage
`
`
`
`Processing Station
`
`
`Location Database
`
`
`

`

`Patent Application Publication
`
`Oct. 10,2002 Sheet 4 of 5
`
`US 2002/0145561 Al
`
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`

`

`Patent Application Publication Oct. 10,2002 Sheet 5 of 5
`
`US 2002/0145561 Al
`
`receive outbound
`
`request?
`
`is there a
`
`databasefor
`
`
`distribution group
`
`monitor relevant data
`in location database
`
`
`
`
`package from Sender
` search userprofiie '
`
`
`no
`
`
`
` send to all
`
`
`user
` send notification to
`
`
`
`
` is there a
`
`match?
`
`notify the user of the
`match
`
`.
`
`
`is there a
`distributin
`
`
`
`
`users in the
`distribution
`group
`
`is the
`
`
`
`parameter
`met?
`
`
`FIG. 6
`
`

`

`US 2002/0145561 Al
`
`Oct. 10, 2002
`
`METHOD AND SYSTEM FOR A PLURALITY OF
`MOBILE UNITS TO LOCATE ONE ANOTHER
`
`BACKGROUND
`
`[0001]
`
`1. Field of the Invention
`
`[0002] The invention relates to a system and a method for
`distributing positional
`information and location specific
`messages to mobile units by using a data network.
`
`[0003]
`
`2. Description of the Related Art
`
`[0004] Global positioning system (“GPS”) is used for
`obtaining position information. The GPSincludesa plurality
`of satellites orbiting the earth and sending out, at precisely
`synchronized times, a code sequence that
`identifies the
`satellite. Specifically, the code sequence transmitted by each
`satellite is a precisely timed binary pulse train. In addition to
`the code sequence,
`these satellites send out positioning
`ioformation that can be used to calculate vehicle positions.
`A GPSreceiver retrieves the positioning information from
`the GPSsatellites and triangulates the information to obtain
`the position of the receiver. A more detailed discussion of a
`GPSreceiver is found in USS. Pat. No. 5,990,827 to Rodric
`C. Fan, et al. entitled “Structure of a Position Processing
`Apparatus,” which is herein incorporated in its entirety.
`
`[0005] Onc application of GPS is vehicle location. A
`conventional vehicle locating system typically includes one
`or more ground stations and a plurality of mobile units that
`may be installed in vehicles. Each mobile unit is equipped
`with a GPS receiver and a wireless transmitter. Using the
`GPSreceiver, a mobile unit determines the position of the
`vehicle in which it is installed and transmits the position to
`a ground station. The ground station of a conventional
`vehicle locating system normally includes a map database
`search system and some type of storage medium that stores
`digital maps and travel-related information. Thus, upon
`receiving the vehicle positions from the mobile units, the
`ground station combines the stored data with the received
`ioformation and displays the present vehicle positions on a
`digital map.
`
`Insomecases, a data network, such as the Internet,
`[0006]
`is involvedin locating mobile units. When a data network is
`involved, the mobile units determine the vehicle positions
`and transmit the position information to the network server.
`This data transmission from a mobile unit to the network
`
`server is accomplished wirclessly by, for example, cellular
`digital packet data network (CDPD)that connects to a data
`network(e.g., the Internet), which in turn provides access to
`the network server. In some cases, the mobile units may
`transmit raw data to the network server so that the network
`
`(MDISs), Mobile Data Base Stations (MDBSs), and Mobile
`End Stations (MESs). An MDBSoffering CDPD services
`helps a roaming MESregister with the MDIS with which the
`particular MDBSis associated by acting as a conduit for the
`registration message. An MDISthat handles the registration
`is referred to as the serving MDIS. Upon receiving the
`registration message from the MDBS, the serving MDIS
`informs the home MDISofthe MESofthe latter’s presence
`in its coverage area. When a host needs to send data to an
`MES, it does not have to be aware of the mobility aspect of
`the MES;
`it simply transmits data using the MES’s IP
`address as the destination address. The encapsulated data
`packets for the MESare forwarded to the serving MDIS of
`the MES. At the serving MDIS, packets are decapsulated to
`reveal
`the MES’s address. The serving MDIS sends the
`original data packets to the right channel where the MESis
`currently located. The MESreceives the data packets. If the
`MESneedsto reply, it directly sends data packets using the
`remote host’s IP address as the destination address. CDPD
`
`systems are further described in K. Budkaet al., “Cellular
`Digital Packet Data Networks,” Bell Labs Technical Journal,
`Vol. 2, No. 3 (Summer 1997); “Cellular Digital Packet Data
`Systems Specification: Relases 1.1,” CDPD Forum,Inc.,
`Chicago (1995); and M. S. Tayloret al., “Internet Mobility:
`The CDPD Approach,” Prentice Hall PTR, Upper Saddle
`River, N.J. (1996).
`
`[0008] The vehicle locating system described above, while
`useful for tracking the fleet of a trucking company or a
`moving company,
`is limited in that the positions of the
`vehicles can only be obtained from a ground station. A
`memberof the fleet cannot use the above vehicle locating
`system to obtain vehicle position information of otherfleet
`members. A method and system that allows one member of
`the fleet to obtain vehicle position information of other
`members of the fleet from a place other than the ground
`station is needed.
`
`SUMMARY OF THE INVENTION
`
`[0009] The present invention includes a system and a
`method for a mobile user to obtain the location of another
`mobile user. A mobile unit tracks its own location through a
`location-determining technology, for example GPS,
`time
`difference of arrival (TDOA),or angle ofarrival (AOA). In
`addition, the mobile unit receives input from users. The
`mobile unit encapsulates the location data and the user input
`in an outbound package, and transmits the outbound pack-
`age to a service provider via a communication network and
`a data network(e.g., the Internet). The service provider is a
`computer that maintains a database of the current location of
`all the mobile units registered with the service provider. The
`database can be accessed byany of the mobile units regis-
`tered with the service provider.
`
`server can make the position determination. In a system that
`involves a networkserver, the data storage medium may be
`accessed by the network serverinstead of the groundstation.
`The data storage medium containstravel-related information
`such as maps,traffic conditions, positionsof service stations,
`and destinations of interest. Thus, the data processing unit
`organizes the measured position and generates an area map.
`The area map indicates by a position marker the position of
`each mobile unit.
`
`[0010] Upon receiving the outbound package from a
`mobile unit, the service provider categorizes the content of
`the outbound packageinto user profile data, announcements,
`and requests. Userprofile data includes personal information
`thal is not localion-specific, such as name, e-mail address,
`telephone number, and hobbies of a user. The service
`provider uses the user profile data to either set up a new
`[0007] As mentioned above, vehicles can connect to data
`account in the database or to modify a pre-existing piece of
`information in the database. Optionally, the service provider
`networks(e.g., the Internet) wirelessly through communi-
`searches the database for a matching entry, and provides the
`cation networks, for example a CDPD network. CDPD
`
`networks consist of Mobile Data Intermediate Systems user withalist of other users who havea similar userprofile.
`
`

`

`US 2002/0145561 Al
`
`Oct. 10, 2002
`
`the
`If the outbound package contains an announcement,
`service provider forwards the announcement to the proper
`recipients indicated in the outbound package, with a location
`stamp indicating the location of the sender mobile unit. The
`outbound package may contain a request, either in addition
`to or instead of an announcement. A request may be a request
`for the location of another user, or a requestto be notified if
`a geographical parameter is met. In response to the former
`type of request, the service provider sends back a response
`package containing the current location ofthe specified user.
`In response to the latter type of request, the service provider
`monitors the location of the relevant mobile unit(s) until
`either the parameter is met or the user sends another out-
`bound package telling the service provider to stop the
`monitoring. When the parameter is met, the service provider
`sends a notification to the requester mobile unit in the form
`of a response package. Depending on the user interface
`device, the notification may include sound, text, flashing
`lights, or graphics.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`(0011] FIG. 1 depicts a location-specific pecr-to-pcer
`communication system in accordance with the present
`invention.
`
`{0012] FIG.2 depicts the components of a mobile unit that
`provides the location data in accordance with the present
`invention.
`
`[0013] FIG. 3 depicts a flowchart of the registration
`process through which a user becomes a part of the com-
`munication system in accordance with the present invention.
`
`[0014] FIG. 4 depicts the components of a service pro-
`vider computer in accordance with the present invention.
`
`announcements and requests into mobile unit 10-i through
`user interface device 12-i, which then combinesthe received
`announcements and requests with location data into an
`outbound package. In some embodiments, for example if
`user interface device 12-i is a laptop or a personal digital
`assistant that allows Internet access, user 14-i may be able
`to enter user profile data through user interface device 12-i
`as well. Mobile unit 10-i transmits the outbound packageto
`communication network 6. Outbound package, as used
`herein, refers to information that originates in user interface
`device 12-i and travels through communication network 6
`and data network 4 to reach service provider 8. Information
`that originates in service provider 8 and travels to mobile
`unit 10-i is referred to as a response package. Mobile unit
`10-i receives a response package, reformats it for user
`interface device 12-i, and passes it to user interface device
`12-i. Communication network 6 includes but is not limited
`to CDPD, GSM, iDEN, AMPS, or CDMA. Data network 4
`is a communication nctwork that can also store and maintain
`data, such as the Internet.
`
`[0019] User 14-i enters announcements and requests into
`mobile unit 10-i through user interface device 12-i, and also
`retrieves any information encapsulated in the response pack-
`age through user interface devices 12-i. User interface
`device 12-1 through 12-n include but
`is not
`limited to
`wireless telephone, laptop, personal digital assistant, and
`pager. ‘hus, after retrieving information from mobile unit
`10-i, user 14-i may contact another user, e.g. user 14”,
`directly without using data network 4. Vor example, if user
`interface device 14 is a wireless phone, user 14-i may call
`user 14-n. Alternatively, if user interface device 14 is a
`laptop, user 14-i may communicate with user 14-n by e-mail
`or instant messaging.
`
`(0015] FIG. 5 depicts an exemplary table of user profiles
`that maintains personal
`information of all users of the
`system.
`
`[0016] FIG. 6 depicts a flowchart of the response-package
`creation process executed by the service provider computer
`in response to an outbound package from a user.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`[0020] FIG. 2 shows the components of mobile unit 10-i.
`Mobile unit 10-2 is a portable unit that can be used inde-
`pendently,
`installed in a vehicle or a cellular phone, or
`clipped onto a watch or a belt. As shown in FIG. 2, mobile
`unit 10-i
`includes GPS receiver 15-i, processor 16-i,
`memory 17-i, and wireless modem 18-i. GPS receiver 15-i
`tunes into the frequency at which GPSsatellites 2 transmit
`information, and receives GPS code sequences. GPS
`recciver 15-i forwards the GPS code sequences to processor
`16-i, which converts the GPS code sequences to location
`data. Processor 16-i uses triangulation to convert the GPS
`[0017] FIG. 1 provides an overview of the location-
`code sequences to preliminary location data by first con-
`specific peer-to-peer communication system in accordance
`verting the GPS code sequences, and then applying the
`correction factors to obtain location data such asastreet
`with the present invention. The system includes GPSsatel-
`lites 2, data network 4, server 6, communication network 6,
`address or latitude, longitude, and altitude. Memory 17-i
`service provider 8, and mobile units 10-1 through 10-1
`includes preliminary location data 19-i and correction factor
`20-i.
`where n is the total number of mobile units in the system.
`Mobile units 10-1 through 10-” are connected to user
`interface device 12-1 through 12-n, respectively. Users 14-1
`through 14-1 transmit information to and receive informa-
`tion from mobile units 10-1 through 10-” through user
`interface device 12-1 through 12-n, respectively.
`
`[0018] As used herein, mobile unit 10-i refers to one
`mobile unit of mobile units 10-1 through 10-1 and user
`interface device 12-i refers to the user interface device that
`is connected to mobile unit 10-7. Mobile units 10-1 through
`10-n receive code sequences from GPS satellites 2 and
`convert the code sequences to location data. In addition,
`mobile units 10-1 through 10-” receive information from
`users 14-1 through 14-n, respectively. User 14-i enters
`
`location data derived from GPS code
`[0021] The
`sequences are stored in memory 17-i. If further calculation
`is necessary to convert
`the location data (e.g.,
`latitude,
`longitude, and maybealtitude) into street address, processor
`16-i cxccutes the necessary calculation before storing the
`values in memory 17-i.
`
`[0022] Processor 16-i uses correction factors 20-i, ¢.g.,
`delta-pseudo-ranges,
`to obtain the actual
`locations (and
`optionally velocities) of mobile units 10-1 through 10-n. The
`correction factors, which depend on the geographical zone in
`which mobile unit 10-7 is located, are obtained from remote
`correction stations (not shown). Processor 16-i can connect
`
`

`

`US 2002/0145561 Al
`
`Oct. 10, 2002
`
`to the remote correction stations via wired or wireless
`as many distribution groups as she wishes. For example,
`communication links, or via a data network such as data
`user 14-i maycreateafirst distribution group including all
`network 4. Using the correction factors received from the
`co-workers, a second distribution group including only the
`remote correction stations and the GPS code sequences,
`co-workers in his project
`team, and a third distribution
`processor 16-i of mobile unit 10-i derives the street
`including his Saturday night poker group. Then,if user 14-i
`addresses and the velocities of mobile units 10-1 through
`can direct a request or an announcementto one or more of
`10-n. The location data may be updated as frequently as
`the distribution groups. Similarly, user 14-i can limit those
`whocan access her current location to those in one or more
`mobile unit 10-i receives the GPS code sequences, or at a
`designated interval such as every two seconds. Further
`distribution groups.
`details on the calculation of location data are provided in
`USS. Pat. No. 5,959,577 to Rodric C. Fan, et. al. entitled
`“Method and Structure for Distribution of Travel Informa-
`
`tion Using Network,” which is herein incorporated in its
`entirety. Processor 16-i reformats the location data to an
`appropriate protocol, e.g., UDP/IP, combines the location
`data with the information entered by user 14-i, and sendsthe
`outbound package to communication network 6 via wireless
`modem 18-i. Processor 16-i tracks the location of mobile
`unit 10-i frequently (c.g., every few seconds) by recciving
`the GPS code sequence, deriving the location data, and
`sending the location data to service provider 8. The frequent
`updating of the location data allows every outbound package
`to have a time stamp and a “location stamp” designating the
`location of mobile unit 10-i at the time the outbound package
`was sent. Further details on location stamp is provided in
`US. patent application Ser. No. 09/696,446 to Carey B. Fan,
`et. al. entitled “Location Authentication Stamp Attached to
`Messages,” which is incorporated herein in its entirety. A
`processor such as Motorola’s MC68331 maybe used for
`processor 16-i.
`registration process
`[0023] FIG. 3 shows the initial
`through which users 14-1 through 14-n becomea partof the
`system in accordance with the present invention. As indi-
`cated by block 30, the registration process begins with the
`subscription process. Block 31 indicates that the subscrip-
`tion process includes physically obtaining mobile unit 10-7,
`for example by purchasing. Block 32 indicates that
`the
`subscription process also includes submitting a unique
`device identification number and/or device IP address to
`service provider 8. Depending on the embodiment, user 14-i
`sends the unique device identification number and/or device
`IP address to service provider 8 by mail, telephone, com-
`putcr, or uscr interface device 12-i. Service provider 8
`receives the device identification number and/or device IP
`address and assigns user 14-i a login name and a password,
`as indicated by block 34. As indicated by block 36, user 14-i
`uses the login name and the password to set up her user
`profile with service provider 8 through data network 4. User
`profile includes personal information such as name, e-mail
`address, residential address, mobile phone number, and
`landline phone number.In addition,user profile may include
`hobbies and interests of user 14-i and distribution groups.
`Distribution groups are further explained below. As shown
`by block 38, user 14-i can modify her user profile as she
`desires. Optionally, the user profile modification may allow
`user 14-i to change her password.
`[0024] User 14-i, who registers with the system in accor-
`dance with the present invention, can access the location of
`all other users who are registered with the system. However,
`user 14-i may wishto limit the data exchange to a sub-group
`of users, such as friends, coworkers, and family. User 14-i
`can limit the data exchange to a sub-group of users by
`defining a distribution group in the user profile. A distribu-
`tion group includesa list of users, and user 14-i can create
`
`[0025] After user 14-i registers with the system,all other
`users have access to the location of user 14-2 In some
`embodiments, user 14-i is provided with a “hide” option in
`the user profile such that if user 14-i opts to “hide,” users
`who normally have access the current location of user 14-i
`is blocked from accessing the current location of user 14-i.
`Some embodiments may allow user 14-/ to specify a list of
`users from whom she wants to “hide. If user 14-i chooses to
`
`“hide” from users 14-2 through 14-5, for example, service
`provider 8 does not provide users 14-2 through 14-5 with the
`location of user 14-i even if users 14-2 through 14-5 request
`the location of user 14-. Instead of providing the location of
`user 14-i, service provider 8 might send a message that the
`location of user 14-i is unavailable.
`
`[0026] After user 14-7 sets up a user profile in service
`provider 8, user 14-2 can access the location data of other
`users by sending outbound packages, as indicated in block
`40, and receiving response packages, as indicated in block
`42. Block 40 indicates that user 14-i can send a request or
`an announcementto service provider8. In the simplest case,
`a request can be a request for the current location of another
`user. Requests and announcements may be entered through
`user interface device 12-i or directly to data network 4,
`depending on the embodiment. A request can entail speci-
`fying a geographical parameter and asking service provider
`8 to send a notification if the geographical parameteris met.
`The geographical parameter may be a pre-defined distance
`relative to user 14-7. For example, user 14-i may request to
`be notified if any user in one of his distribution groups
`comeswithin a ten-mile radius. Alternatively, the geographi-
`cal parameter may be defined independently of the location
`of user 14-7 For example, user 14-i may request to be
`notified if user 14-2 crosses a specific zip code, passes a
`landmark,or arrives at a specific intersection or restaurant.
`In that case, service provider 8 sends user 14-7 a response
`package containing a notification when the condition is
`satisfied.
`
`[0027] FIG. 4 shows the components of service provider
`8. Service provider 8 may be a computeror a server linked
`to data network 4. Service provider 8 includes processing
`station 40, user profile database 42, map storage 44, and
`location database 46. Userprofile database 42 stores the user
`profiles of all users 14-1 through 14-n. If a user modifies
`his/her user profile, processing station 40 updates user
`profile database 42 accordingly. Map storage 44 stores maps
`of the geographical area covered by service provider 8. Map
`storage 44 allows user 14-i to see a map of the relevant area
`if desired. For example, if user 14-7 requests to be notified
`if user 14-2 is within a ten-mile radius, processing station 40
`may provide user 14-i with a map showing the location of
`user 14-2 relative to the location of user 14-i. Location
`database 46 contains data that is more frequently updated
`than user profile data, such as the locations of mobile units
`10-1 through 10-n. As mentioned above, location data may
`
`

`

`US 2002/0145561 Al
`
`Oct. 10, 2002
`
`be updated as frequently as every two seconds. When users
`make requests, the geographical parameters maybe stored in
`location database 46 as well. Similarly, when users make
`announcements, the content of the announcements may be
`stored in location database 46.
`
`[0028] User profile database 42, map storage 44, and
`location database 44 may be implemented using any mass
`storage media, such as hard disks, RAMs, ROMs, CD-
`ROMs,and magnetic tapes. Infrequently updated informa-
`tion, such as maps or uscr profile, may be stored on
`CD-ROMs.Onthe other hand, frequently updated informa-
`tion, such as location data, may be stored on RAM.
`
`In some embodiments, user profile database 42
`[0029]
`may store the user profiles in a table format. FIG. 5 shows
`exemplary table 50 which may be used to store the user
`profiles in user profile database 42. Table 50 stores personal
`information such as name, residential address, home tele-
`phone number, mobile telephone number, e-mail address,
`hobbies, and distribution lists, as shown by columns 53, 54,
`55, 56, 57, 58, and 59. The exemplary table 50 in FIG. 5
`indexes the information by user numbers, as shown in
`column 51. Other embodiments may index the personal
`information by device identification number (column 53) or
`by IP address (not shown). Location database 46 may be
`indexed similarly.
`
`[0030] FIG.6 illustrates the functions of service provider
`8. Upon receiving an outbound package (block 60) from a
`sender, processing station 40 sorts the data encapsulated in
`the outbound packageinto user profile, announcements, and
`requests, as indicated in blocks 70, 80, and 90. If the
`outbound package contains user profile data, processing
`station 40 accesses user profile database 42 to enter the
`newly-reccived user profile. As indicated in block 72, if the
`sender is a new user, processing station 40 creates a new
`entry for the sender and stores the received user profile for
`the sender. If the sender is a user who previously set up a
`user profile, processing station 40 updates the user profile
`data for the sender. In some embodiments, processing station
`40 scans userprofile database and looks for a matching entry
`when entering or modifying a user profile, as indicated in
`block 74. A matching entry may be, for example, other users
`whoshare the same hobbies andinterests, or other users who
`live in the same neighborhood as the sender. Processing
`station 40 may find a match by looking for a matching word
`in every row of the exemplary table 50 (FIG. 5). Upon
`finding a match (block 76), processing station 40 creates a
`response package to the sender and transmits to data net-
`work 4 a list of users found to have matching entries, as
`indicated in block 78. If there is no match, processing station
`40 may send a response package stating that there is no
`match and move on to other parts of the outbound package
`received in block 60.
`
`[0031] Blocks 82 and 84 indicate that if the outbound
`package received in block 60 contains an announcement,
`processing station 40 accesses user profile database 42 and
`checks to see if the sender specified a distribution group,
`either previously or in the outbound package. If there is a
`distribution group, processing station 40
`sends
`the
`announcement to all the users in the distribution group, as
`indicated in block 86. If there is more than one distribution
`group, the outbound package should indicatethe distribution
`group to which the announcement should besent. If there is
`
`no distribution group or the outbound package specifies no
`distribution group, processing station
`40 sends
`the
`announcement to all users, as indicated in block 88. All
`announcements sent can contain a location stamp indicating
`the current location of the sender. Thus, if the announcement
`is “meet for dinner at 7 p.m. in Restaurant X,” a recipient of
`the announcementcan see the location of the sender. If the
`
`sender is in the vicinity of the recipient, the recipient may
`contact the sender and ask to share a ride.
`
`If the outbound package received in block 60
`[0032]
`contains a request, block 92 indicates that processing station
`42 identifies the parameter specified by the sender. In the
`simplest request, the parameter may include only the name
`of a target user whose location the sender wants to know.
`Upon receiving such request, service provider8 retrieves the
`current location ofthe target user from location database and
`transmits it to the sender in a response package. A request
`may include a geographical parameter in addition to the
`name of a target user. If, for example,
`the geographical
`parameteris “within a 10-mile radius,” processing station 40
`accesses location database 46 to obtain the location of the
`
`target user and the location of the sender and monitors the
`two locations (block 94). Processor 40 uses map storage 44
`to determine the distance between the target user and the
`sender every time newlocation data is entered (e.g., every
`two seconds), as indicated in block 96. When the location
`between the sender and the target user are within the
`specified geographical parameter, which is within ten miles
`of each other in this example, processing station 40 transmits
`a response package to the sender. The response package,
`which contains a notification, is transmitted to data network
`4. Data network 4 forwards the notification to communica-
`tion network 6, which transmits the notification to mobile
`unit 10-7. The sender receives the notification from mobile
`
`unit 10-i through user interface device 12-i.
`
`In the simple case where the request only contains
`[0033]
`the identity of a target user whose location the sender wishes
`to know, the notification contains the current location of the
`target user. If the request contained a geographical parameter
`(e.g., within a 10-mile radius), the notification may be a beep
`or a flashing text. Any notification may include sound,
`flashing lights, text, or graphics depending on the embodi-
`ment and user interface device 12-i. Upon receiving the
`notification, the sender (user 14-i) may take a responsive
`action, for example by directly contacting the target user.
`The user-to-user (peer-to-peer) communication may be in
`the form of a phone call, e-mail,
`instant messaging, or
`chatting. If the uscr-to-uscr communication involves user
`interface device 14-i, the exchanged messages may have a
`location stamp even if the communication does not involve
`service provider 8, because mobile unit 10-i derives and
`stores location data.
`
`invention is illustrated with
`[0034] While the present
`particular embodiments, it is not intended that the scope of
`the invention be limited to the specific and preferred
`embodiments
`illustrated and described. For example,
`although the disclosed embodiments refer to GPS as the
`location-identification method used, other methods such as
`time difference of arrival (TDOA), angle of arrival (AOA),
`ray tracing/pattern recognition, and hybrid methods using
`network connections may be used.
`
`

`

`US 2002/0145561 Al
`
`Oct. 10, 2002
`
`Whatis claimedis:
`1. Amethodof providing the location of a second mobile
`unit to a first mobile unit, said method comprising:
`
`receiving from said first mobile unit a first packet includ-
`ing a current location of said first mobile unit;
`
`receiving from said second mobile unit a second packet
`including a current location of said second mobile unit;
`
`storing said current locations in a database; and
`
`transmitting a data package to said first mobile unit in
`response to a request
`from said first mobile unit,
`wherein said data package comprises said current loca-
`tion of said second mobile unit retrieved from said
`database.
`
`2. The method of claim 1, wherein said receiving and said
`storing are repeated at a regular time interval.
`3. The method of claim 1, said packet further providing at
`Icast oneof:
`
`personal information about a first user, said first user
`being a user of said first mobile unit;
`
`an announcement; and
`
`9. The method of claim 1, wherein said receiving and said
`transmitting are done through a data network.
`10. The method of claim 9, wherein said data nctwork
`comprises the Internet.
`11. The method of claim 9, wherein said data network
`comprises a wircless communication nctwork, said wircless
`communication network being selected from a group con-
`sisting of CDPD, CDMA, GSM, iDEN, and AMPS.
`12. The method of claim 3, further comprising excluding
`said first mobile unit from a group of