U.S. patent application number 09/903982 was filed with the patent office on 2003-01-16 for monitoring boundary crossings in a wireless network.
Invention is credited to Fitch, James A., Hose, David A..
Application Number | 20030013449 09/903982 |
Document ID | / |
Family ID | 25418335 |
Filed Date | 2003-01-16 |
United States Patent
Application |
20030013449 |
Kind Code |
A1 |
Hose, David A. ; et
al. |
January 16, 2003 |
Monitoring boundary crossings in a wireless network
Abstract
A process (400) according to one implementation of the present
invention is initiated by receiving (402) a service zone definition
for a boundary crossing. The boundary crossings application further
receives (404) a monitoring request. For example, a vehicle rental
company may enter the MIN/ESN of all mobile units associated with
vehicles that are to be monitored, the timeframes during which the
vehicles are to be monitored and the specific zones or boundaries
with respect to which vehicle movement is to be monitored.
Movements of the mobile unit or units of interest can then be
monitored by receiving and storing (406) current location
information, retrieving (408) prior location information for the
mobile unit or units, and using (410) the current and prior
location information to determine whether a service zone boundary
has been crossed during the intervening time interval. Once a
determination is made (412) as to whether a boundary crossing has
occurred, the boundary crossing application may continue monitoring
mobile unit location/movement and/or may generate (414) service
information according to application parameters. The service
information is then transmitted (416) according to application
parameters. Such application parameters may specify the recipient,
content and format of the service information.
Inventors: |
Hose, David A.; (Boulder,
CO) ; Fitch, James A.; (Edmonds, WA) |
Correspondence
Address: |
MARSH FISCHMANN & BREYFOGLE LLP/OPENWAVE SYSTEM
INC.
3151 SOUTH VAUGHN WAY
SUITE 411
AURORA
CO
80014
US
|
Family ID: |
25418335 |
Appl. No.: |
09/903982 |
Filed: |
July 11, 2001 |
Current U.S.
Class: |
455/440 |
Current CPC
Class: |
H04W 4/02 20130101; G08G
1/207 20130101; H04W 8/08 20130101; H04W 4/021 20130101 |
Class at
Publication: |
455/440 ;
455/456; 455/414 |
International
Class: |
H04Q 007/20 |
Claims
1. A method for use in providing services based on the locations of
mobile units in a wireless communications network, said wireless
network including a switch structure for use in selectively routing
communications between network users and a processing platform
associated with the switch structure, said method comprising the
steps of: providing a location based services application running,
at least in part, on the processing platform associated with the
switch structure; defining at least one geographic reference for
said location based services application; storing an identifier for
a mobile unit of interest to a user; monitoring a location of said
mobile unit, using said location based services application and
said identifier of said mobile unit, to identify an attainment of a
predetermined relationship of said mobile unit relative to said
geographic reference, said attainment being defined by a change of
status with respect to said predetermined relationship; and
transmitting service information regarding said mobile unit in
response to said attainment of said predetermined relationship of
said mobile unit relative to said geographic reference.
2. A method as set forth in claim 1, wherein said step of defining
said geographic reference comprises receiving subscriber specific
information from said user regarding said geographic reference and
said step of storing comprises indexing information regarding said
geographical reference to said identifier.
3. A method as set forth in claim 1, wherein said step of defining
comprises identifying a geographical area for which said user
desires to receive notification upon one of: a) entry of said
mobile unit into said identified geographical area; and b) exit of
said mobile unit from said identified geographical area; and said
step of transmitting comprises providing notification to said user
of said boundary crossing event.
4. A method as set forth in claim 1, wherein said step of defining
comprises receiving zone location information regarding a service
zone referenced to a first topology system and expressing said zone
location information in terms of a second topology system of said
location based services application.
5. A method as set forth in claim 4, wherein said first topology
system comprises a street grid.
6. A method as set forth in claim 4, wherein said second topology
system comprises one of a geographical coordinate system and a
system of wireless network subdivision identifiers.
7. A method as set forth in claim 1, wherein said step of providing
a location based services application comprises providing an
application for allowing a person of authority to monitor the
movements of one of a person or a vehicle associated with said
mobile unit.
8. A method as set forth in claim 1, wherein said step of providing
a location based services application comprises providing an
application for setting a billing parameter for use of said
wireless network by said mobile unit.
9. A method as set forth in claim 1, wherein said step of
monitoring comprises storing first location information regarding a
first location of said mobile unit at a first time, obtaining
second location information regarding a second location of said
mobile unit at a second time and comparing said first location
information to said second location information to identify said
attainment of said predetermined relationship.
10. A method as set forth in claim 9, wherein said first location
information comprises a first zone identifier for a particular
service zone and said second location information comprises a
second zone identifier for a particular service zone, and said step
of comparing comprises determining whether said first zone
identifier is the same as said second zone identifier.
11. A method as set forth in claim 9, wherein said step of
monitoring further comprises defining a geometrical element
interconnecting a first location of said first location information
and a second location of said second location information and
determining whether there is an intersection between said
geometrical element and a boundary of a service zone.
12. A method as set forth in claim 1, wherein said unit is a
telephone and said step of storing an identifier comprises storing
an MIN/ESN.
13. A method as set forth in claim 1, wherein said step of
transmitting service information comprises transmitting said
service information to said mobile unit.
14. A method as set forth in claim 1, wherein said step of
transmitting service information comprises transmitting said
service information to a data network node associated with said
subscriber, said data network node being separate from said mobile
unit.
15. A method as set forth in claim 1, wherein said step of
transmitting service information comprises transmitting said
service information to a separate application that is registered
with said location based services application to receive boundary
crossing information regarding said mobile unit.
16. A method as set forth in claim 1, wherein said step of
transmitting service information comprises transmitting a message
to said user providing notice of a boundary crossing event.
17. A method as set forth in claim 16, wherein said message
comprises one of a voice, text or graphical message.
18. A method as set forth in claim 1, wherein said step of
transmitting service information comprises transmitting one of
local service information and local emergency condition information
to said mobile unit.
19. A method for use in providing services, based on the locations
of mobile units in a wireless network, comprising the steps of:
establishing a location based services system, including a
processing platform and data storage associated with the processing
platform; said location based services system being interconnected
to a network location finding system for receiving network location
information therefrom regarding the location of the mobile units
within the wireless network, said network location finding system
being operative for determining said network location information
regarding said mobile units based on locations of the mobile units
and known locations of network structure in said wireless network;
said location based services system further being interconnected to
a system user via a communication network including a switch
structure for routing communications based on an address whereby
user information can be transmitted from said location based
services system to said user by associating said user information
with a user address; said location based services system further
being associated with a data input port for receiving information
for storage in said data storage and for use by said location based
services system; first receiving, via said data input port, service
zone information identifying a geographic service zone including at
least one service zone boundary; first storing said service zone
information in said data storage of said location based service
system; second receiving, via said data input port, an identifier
identifying a mobile unit of interest to said system user; second
storing said identifier in said data storage of said location based
service system; third receiving, from said network location finding
system, said network location information including mobile unit
location information regarding said mobile unit of interest; third
storing said mobile unit location information in said data storage
of said location based service system; first operating said
location based service system to 1) monitor locations of said
mobile unit of interest over a time period, 2) make a comparison
based on one or more of said monitored locations of mobile unit
location to said service zone boundary, and 3) based on said
comparison, identify a crossing of said service zone boundary by
said mobile unit of interest; and second operating said location
based service system to 1) generate service information in response
to said identified crossing of said service zone boundary, 2)
establish a user communication including said service information
and information identifying said user address, and 3) transmitting
said user communication to said system user; wherein said system
user receives service information triggered by said crossing of
said service zone boundary.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to providing
location-based services in a wireless network and, in particular,
to providing service information based on the crossing of a service
zone boundary by a mobile unit in a wireless network.
BACKGROUND OF THE INVENTION
[0002] A number of different types of location based service
applications have been developed or proposed for wireless networks,
i.e., communications networks involving at least one wireless
interface between communicating devices. Generally, such
applications determine or otherwise obtain location information
regarding the location of a mobile unit under consideration, e.g.,
a wireless telephone, PDA, wireless data terminal or the like--and
provide service information based on the mobile unit location.
Examples of location based service applications include E911, local
service information and location-based billing applications. In
E911 applications, emergency calls are routed to a selected
dispatcher based on the location of origin of an emergency call.
Location based service applications provide information regarding
local services such as hotels or restaurants based on a request
entered via a mobile unit. In location based billing applications,
a rate for a call placed or received by a wireless telephone is
dependent on the location of the phone, e.g., whether the phone is
inside or outside of a "home zone" for the subscriber proximate to
the subscriber's residence, business or other defined location.
Various other applications have been proposed or implemented.
[0003] Location based service applications generally involve
comparing a current (or recent) location to predefined service zone
definitions to make either a binary determination (e.g., that the
mobile unit is either inside or outside of a zone under
consideration) or a matching determination (e.g., that the mobile
unit location matches or overlaps one or more stored zone
definitions). In either case, at one or more relevant processing
steps, mobile unit location information corresponding to a
particular time is compared to service location information
corresponding to one or more service zones, service provided
locations or other stored location information. Thus, in E911
applications the mobile unit location at the time of placing an
E911 call may be compared to the dispatcher coverage zones of an
emergency response network. In local service information
applications, the location of a mobile unit at the time of
submitting, for example, a local hotel information request, may be
compared to a database of hotel location information. The location
of a mobile unit during a call may be used by a location based
billing application to establish billing parameters for the
call.
[0004] In addition, location based service applications generally
provide service information in response to an input by a subscriber
or other application user invoking the application. In the case of
local service information applications, the input is generally an
explicit service request entered via the mobile unit. In E911 or
location based billing applications, the location based service
application may be invoked invisibly, from the perspective of the
mobile unit, upon making a call. In other cases, the input invoking
the application to provide service information based on the
location of the mobile unit, is received from an application
separate or remote from the mobile unit requesting location based
service information, e.g., identification of current mobile unit
location. In such applications, the service information is
nonetheless provided in response to an input requesting
location-based services. That is, the trigger event generally is,
from the perspective of the service application, a service
request.
SUMMARY OF THE INVENTION
[0005] The present inventors have recognized that certain
location-based service application functionality can be supported
and enhanced by generating service information based on the
location or movement of a mobile unit rather than in response to a
service request from a subscriber, separate application or other
system user or based on other criterion such as periodic reporting.
In this manner, events associated with the movement of a mobile
unit can be identified as may be desired for a variety of
applications. Moreover, movement of an identified mobile unit
relative to a geographic reference such as a service zone boundary
can be monitored with minimal user inputs or communications between
a location managing system and an associated wireless location
based service application.
[0006] According to one aspect of the present invention, a method
is provided for generating service information based on a location
input regarding a mobile unit under consideration. The method
includes the steps of: providing a location based services
application running, at least in part, on a processing platform of
a wireless network; receiving an input identifying a location
parameter to be monitored for a mobile unit; storing the location
parameter; receiving location information regarding the current
location of the mobile unit; in response to the received location
information, comparing the location information to the stored
location parameter; and, based on the comparison, selectively
generating service information regarding the mobile unit.
Generation of service information is thereby triggered by the
received location information and the associated comparison to a
stored location parameter. The service information can be
transmitted to the monitored mobile unit, another mobile unit, a
network node remote from the monitor mobile unit and/or a further
application.
[0007] According to another aspect of the present invention, a
mobile unit is monitored to identify attainment of a predetermined
relationship relative to a geographic reference such as the
crossing of service zone boundary. The associated method includes
the steps of: providing a location based services application
running, at least in part, on a processing platform of a wireless
network; defining at least one geographic reference for the
application, where the reference can be used to identify attainment
of a predetermined positional relationship by the mobile unit;
storing an identifier for the mobile unit or units of interest to a
subscriber; monitoring a location of the mobile unit, using the
application and the identifier of the mobile unit, to identify
attainment of the predetermined positional relationship; and
transmitting service information regarding the mobile unit in
response to the identified attainment of the predetermined
relationship. The invention has particular advantages for providing
service information in response to a flux of the mobile unit
relative to the geographic reference such as traversing a service
zone boundary. Thus, service information may be generated based on
identification of a boundary crossing or other location related
change in status rather than in direct response to a service
request from a system user or based on a periodic or occasional
polling process.
[0008] The above noted functionality can be used to support and
enhance a variety of applications. In certain applications, it is
desired to provide notification when a mobile unit crosses a
defined boundary. For example, a car rental company, or other fleet
manager, may wish to be notified if a vehicle enters a proscribed
area (e.g., crosses into a prohibited country) or exits a permitted
area. Similarly, a parent, government official or other person in a
position of authority may wish to monitor the movement of a child
or other person or charge to insure that such charge has not
entered a prohibited area or left a permitted area or area of
confinement. In other applications, mobile unit location may be
monitored relative to service zone boundaries to re-rate calls or
to provide emergency or other service information to a subscriber
upon entering a given service zone. In still other applications, a
system user may wish to be notified when a mobile unit comes within
a defined radius of a defined location, moves West, East, etc. of a
defined location or attains a defined location in relation to the
current location of another mobile unit. In another type of
application, the boundary or other geographic reference may be
defined at, or close to, the time of the location comparison rather
than being predefined a substantial time prior to the comparison.
For example, an application may notify a subject mobile unit when
it comes within a certain distance of one or more other identified
mobile units or vice versa. Such an application may be useful for
helping friends or family members to rendezvous.
[0009] The present invention advantageously allows for monitoring
position and movement of mobile units utilizing existing network
structure. In this regard, location information for a mobile unit
of interest can be obtained from a network assisted location
finding system where location is determined based at least in part
on the position of a mobile unit relative to a known location of a
network structure, e.g., cell location, cell sector, AOA, TDOA, a
GPS assist receiver system, a network overlay location transceiver,
etc. The use of such network based location finding technologies
allows applications in accordance with the present invention to
service a variety of mobile units systems including conventional
wireless phones and other devices without dedicated location
equipment such as GPS transceivers. Thus, such applications can
support a greater number of subscribers without specialized
handsets or other subscriber equipment dedicated to location
determination. Moreover, systems in accordance with the present
invention can be implemented at least in part on network structure
such as processing platforms associated with a network switch. For
example, a location management system maybe associated with such a
platform to receive location information, and provide notification
information to a wireless location application when a mobile unit
under consideration attains a predetermined relationship relative
to a stored geographic reference. By utilizing such network
structure, rather than implementing such functionality on an
on-board computer or other subscriber equipment, the associated
application can have convenient access to a centralized database
which may be conveniently updated to provide more current
information. Moreover, implementing such applications in connection
with existing structure allows network providers, carriers and the
like to make enhanced services available to existing subscribers
and to thereby distinguish themselves from competing service
providers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a more complete understanding of the present invention
and further advantages thereof, reference is now made to the
following detailed description, taken in conjunction with the
drawings, in which:
[0011] FIG. 1 illustrates the representation of a service zone
boundary in accordance with the present invention using a
cell-sector based location finding technology;
[0012] FIG. 2 illustrates activity that may be deemed a service
zone boundary crossing in accordance with the present
invention;
[0013] FIG. 3 shows a wireless network implementing the system of
the present invention; and
[0014] FIG. 4 is a flow chart illustrating a preferred
implementation of the present invention.
DETAILED DESCRIPTION
[0015] The present invention is directed to a method and system for
providing service information in a wireless network in response to
and based on a comparison of mobile unit location information to a
stored geographic reference information. The following description
includes an initial discussion of exemplary applications that are
supported by the present invention, followed by a description of
the preferred network for implementation of the invention and then
a description of preferred processes for implementing the
invention.
[0016] A. Applications
[0017] The present invention supports a number of applications
where service information is generated in response to detection of
a mobile unit attaining a particular position in relation to a
geographic reference, e.g., detection of a service zone boundary
crossing. A number of examples of such applications are described
below. It will be appreciated that many more examples are possible.
Nonetheless, the following examples illustrate that such
applications can vary, for example, with respect to the types of
service information that are generated as well as how and to whom
or what the service is reported.
[0018] One type of application where it may be desired to monitor
boundary crossings relates to fleet management such as rental
vehicle tracking. Rental vehicles may be tracked to insure that the
tracked rental vehicle is being used in accordance with the rental
contract, e.g., that the vehicle is not being taken across certain
national borders. Boundary crossings may be proscribed due to
insurance limitations, political/social considerations or other
reasons. The rental company may therefore desire to receive
notification when boundary crossings occur. It will be appreciated
that the rental company would not necessarily require continual
updates of vehicle locations (though some companies may choose to
obtain such updates) but, most importantly for present purposes,
will desire notification triggered by a boundary crossing
event.
[0019] Such notification can be conveniently provided via a data
network such as the Internet. In this manner, an official of the
rental company may receive a graphical or text notification
identifying the monitored vehicle and the boundary crossing event,
e.g., "ID #nnn has crossed into/out of the United States." In
response to such notification, the rental company may contact the
lessee (e.g., by car phone) remotely disable the rental vehicle,
assess a contractual penalty or take other remedial measures.
[0020] As will be discussed in more detail below, such a boundary
crossing event can be identified using a conventional wireless
telephone or other mobile unit carried by the rental vehicle and,
preferably, configured to remain powered on when the vehicle is in
use. Such a monitoring application can take advantage of existing
wireless network platforms and location finding equipment to
provide monitoring with minimal, if any, equipment on board the
rental vehicle dedicated to position monitoring, thereby reducing
costs and facilitating rapid deployment. As described below, a
wireless network platform remotely or locally associated with a
network switch can be connected to one or more location finding
equipment systems for receiving location information regarding the
monitored vehicle or its on-board mobile unit and can be further
connected to a data network for providing reports to the rental
company's data terminal.
[0021] Another type of application where it may be desired to
monitor boundary crossings is location based billing applications.
In these applications, the rate applied for calls placed or
received using a wireless telephone depends on the location of the
phone. For example, wireless carriers may wish to encourage
subscribers to use their wireless phones as their only phones by
providing call rating competitive with land line phones for calls
placed in or near the subscriber's home, office or other defined
location, but providing a different rating for calls placed or
received outside such "home zones." The relevant rating information
may be provided to a billing system of the carrier or other service
provider by populating an associated field of a Call Detail Record
(CDR) with a billing value.
[0022] In connection with such applications, it may be desired to
monitor boundary crossings for a number of reasons. For example,
identifying crossings into or out of a home zone may be used to
re-rate an ongoing call or otherwise re-set a billing parameter.
Also, it may be useful to provide an indication to the subscriber
regarding location relative to a home zone, e.g., via a display
element on the handset, so that the subscriber can know in advance
of a call what rates may apply. Thus, boundary crossings may be
monitored in order to transmit messages to the mobile unit causing
the display element to toggle between "home zone" and "outside home
zone" displays. In the case of call re-rating, a single call may be
divided into parts billed at different rates, e.g., by generating
multiple CDRs, or a single rate may be selected based on a boundary
crossing. In either case, the service information provided by the
application may simply be a rating value and the recipient may be a
billing application.
[0023] A final example of applications that may make use of
boundary crossing information is a local service or friend
notification application. Such an application may provide emergency
information--e.g., regarding local traffic, weather, or other
emergency conditions--or other service information--e.g.,
information about local hotels, restaurants or other services--to
all or subscribing system users upon entry into a service area. For
example, in the case of severe weather warnings, a traveler may be
notified by phone or display upon entering the affected area (such
as on crossing a county line). For a traffic jam, warnings and
alternative route or other information may be provided to commuters
coming within a certain area encompassing the problem location.
Similarly, local service providers may transmit pricing, event or
other service information to willing, approaching travelers. In the
case of "friend" notification, a subscribing system user and/or an
identified "friend" may be notified when the user comes within a
certain proximity of the mobile unit of the friend or the friend
comes within a certain proximity of the user. In such cases, the
"boundary" may be defined and redefined "on the fly".
[0024] In such cases, service information may be transmitted to the
monitored mobile unit, an associated data terminal or other device
proximate to the monitored unit. The information may be provided in
audio, text, graphical or other form depending, for example, on the
limitations of the user equipment and the type of information
required. Transmission of the service information may be triggered
by crossing a political or government boundary, crossing within a
radius of a location of interest or otherwise crossing a service
zone boundary of any shape.
[0025] As the foregoing examples illustrate, the type of service
information, form of service information transmission, intended
recipient and other details can vary from application to
application or even within a particular application in accordance
with the present invention. This will be further understood upon
consideration of a preferred network environment of the present
invention as described below.
[0026] B. Network Environment
[0027] The present invention can be implemented in a wireless
communications network such as a wireless telephone network. Such
an implementation has a number of advantages. First, in many cases,
wireless networks have access to location information regarding
mobile units located within the wireless network or certain areas
thereof from existing location finding equipment. In many cases,
such location finding equipment is capable of providing location
information for any mobile unit within the coverage area. Moreover,
certain location finding technologies can provide location
information without requiring any specialized subscriber equipment
dedicated to location finding. In addition, the present invention
can make use of existing network structure such as processing
platforms and switching equipment to access location information,
perform location calculations as desired and route service
information to system users. In this manner, a system for providing
service information in accordance with the present invention can be
readily implemented. Moreover, such services can be marketed to
wireless network subscribers, and service providers who desire
access to such subscribers, thereby facilitating system deployment
and enabling wireless carries to provide a value added service that
may distinguish the carrier from competitors.
[0028] Various types of location finding systems can be used in
accordance with the present invention. Preferably, the location
finding system is a network assisted technology such as AOA, TDOA,
network assisted GPS, cell sector or similar network based system
thereby making use of existing technology associated with the
wireless network. In one embodiment, the location finding system
employed is a fully network based system such as a cell sector
system that provides location information regarding a mobile unit
of interest without requiring any mobile unit based equipment
dedicated to location determination. In addition to cell sector
technology, such systems included AOA, TDOA and the like.
[0029] FIG. 1 illustrates a wireless network 100 utilizing a cell
sector technology to represent a service boundary 108. The network
100 includes a number of cell sites 102 each having an associated
coverage area 104 within which cell site equipment can communicate
with mobile units via RF signals. As shown, the coverage areas 104
of each cell may be irregular in shape due to, for example, local
geography and other local signal transmission characteristics.
Moreover, the coverage areas 104 may overlap as shown to insure
relatively complete coverage. Coverage areas may also overlap in
order to provide better service in high usage areas of the
network.
[0030] A cell site 102 may include a number of directional antennas
that effectively divide the coverage 104 into a number of sectors
106. In the illustrated embodiments, individual cells are divided
into three sectors 106, each of which covers approximately 120
degrees of the coverage area 104 surrounding the cell site 102.
Thus, each sector 106 encompasses a generally wedge-shaped
area.
[0031] A location finding system utilizing cell sector technology
provides a somewhat coarse indication of mobile unit location. In
particular, the location of a mobile unit is approximately known by
determining which cell sector antenna is handling communications
with the mobile unit. Based on this information, the mobile unit is
deemed to be within the associated generally wedge-shaped area. For
processing purposes, the associated location may be expressed as a
two-dimensional coordinate location, e.g., representing a center
point of the generally wedge-shaped area, and an uncertainty area,
e.g., defined by an uncertainty radius. Such an uncertainty radius
may be selected to reflect the uncertainty inherent in the cell
sector technology. It will be appreciated that alternative location
finding technologies may provide greater accuracy. For example,
AOA, and TDOA methodologies are capable of providing greater
accuracy than cell sector technologies. Moreover, in areas of a
wireless network where more than one location finding technology is
available, location information from multiple location finding
technologies, or the raw location information from which location
determinations are made using one or more of the technologies, may
be combined to provide even greater accuracy.
[0032] In FIG. 1, the dashed line 108 represents a service zone
boundary. For present purposes, the area to the right of the
service zone boundary 108 may be taken to define a service zone
such as a zone within which authorities wish to disseminate
emergency information. In the illustrated network 100 which
utilizes a cell sector based location finding technology, the
boundary 108 and associated service zone are approximated by a set
of cell sectors. These cell sectors are the shaded sectors 106 in
FIG. 1. It will thus be observed that the shaded cell sectors 106
generally coincide with the service zone, although the boundary 108
is only followed imperfectly. In the illustrated example, the
service zone definition depicted by the shaded cell sectors is over
inclusive in that any cell sector that is at least partially within
the service zone is included in the service zone definition. As a
practical matter, this means that any mobile unit that may or may
not be within the surface zone due to the uncertainty inherit in
the cell sector technology may be deemed to have crossed the
boundary 108 and may therefore receive the emergency
information.
[0033] More specifically, the system of the present invention can
provide service information based on a boundary crossing
determination as opposed to, for example, a binary determination
that a mobile unit is either inside or outside a service zone at a
particular instant in time. This is illustrated in FIG. 2. In FIG.
2, the location of a mobile unit is indicated by a point, e.g.,
defined by two-dimensional coordinates, and an uncertainty area
102. In the illustrated implementation, the uncertain area is taken
to be defined by an uncertainty radius surrounding the point 200,
but it should be appreciated that uncertainty areas of other shapes
may be utilized. In FIG. 2, a current location of a mobile unit is
shown in solid lines and a prior location of the mobile unit is
shown in dashed lines. The presumed movement of the mobile unit
between the two times is therefore indicated by arrow 206.
[0034] FIG. 2 illustrates activity that may be characterized as a
boundary crossing. In particular, reference numeral 204 indicates a
service zone boundary. In this case, the boundary 204 defines a
service zone of complex shape as may be desired in a particular
application. At the first time, the location of the mobile unit as
indicated by the point 200 and the uncertainty area 202 is fully
located on a first side of the boundary 204. At the second time,
the location of the mobile unit as indicated by the point 200 and
the uncertainty area 202 is undetermined with respect to the
boundary 204. That is, a portion of the uncertainty area 202 at the
second time overlaps a portion of the service zone. Accordingly,
the mobile unit may be within the service zone. This change in
status from the first time to the second time (i.e., from "outside"
the service zone to "potentially inside") may be deemed a boundary
crossing event for the purposes of a particular application. It
will be appreciated that a boundary crossing event may similarly be
indicated by a change in status from clearly outside the service
zone to clearly inside the service zone, i.e. where the entire
uncertainty area at the second time is within the service zone.
[0035] The example of FIG. 2 suggests one mathematical analysis for
identifying a boundary crossing event. Specifically, a change in
status between the first time and the second time is determined
relative to an overlapping area analysis. At the first time, the
area of overlap between the uncertainty area 202 and the service
zone is a mathematical nullity. At the second time, there is an
intersection between a set of area units comprising the uncertainty
area 202 and the set of area units comprising the service zone. For
example, the area units may be elements of a Quadtree data
structure utilized to represent the area of a wireless network such
as described in co-pending U.S. patent application Ser. No.
09/788,036 which is incorporated herein by reference in its
entirety.
[0036] It will be appreciated that a variety of other mathematical
models may be utilized in accordance with the present invention to
identify a boundary crossing relative to first and second location
information. For example, a first mathematical representation may
be defined to represent a line segment or other geometric element
interconnecting the first point 200 (associated with the first
time) and the second point 200 (associated with the second time) or
the first area 202 and the second area 202 and a second
mathematical representation may be utilized to define the boundary
204. These mathematical representations may then be compared e.g.,
by simultaneously solving equations, to identify any intersection.
Alternatively, a ray may be defined emanating from the point 200 at
the first time in a selected direction. Another ray may be defined
emanating from the point 200 at the second time in the same or a
different direction. At each time, the number of instances that the
ray crosses the boundary 204 may be determined to thereby provide
an indication that the point under consideration is inside or
outside of the service area. Any change in status in this regard
between the first time and the second time would be indicative of a
boundary crossing. Many other solutions are possible as will be
appreciated as one skilled in the art.
[0037] For many applications, identifying a boundary crossing may
provide advantages relative to generating service information based
on a binary determination that a mobile unit is located within or
outside a service area at an instant in time. For example, it may
be desirable to provide emergency information or local service
information only upon entering a service zone rather than
continuously while a mobile unit is located within a service zone.
This objective can be achieved by triggering transmission of the
service information based on a boundary crossing rather than based
on a determination that the mobile unit is inside of the service
zone. Moreover, in other contexts, transmissions between a network
platform and a mobile unit may be reduced thereby conserving
bandwidth. For example, as noted above, in a location based billing
application, it may be desirable to provide an indication on a
display of the mobile unit indicating that the mobile unit is
either inside or outside of a home zone. Such information may be
transmitted from a network platform to a mobile unit. In order to
minimize such transmissions, updated information may be transferred
to the mobile unit only upon a change in status with regard to the
home zone boundaries.
[0038] FIG. 3 illustrates a wireless network 300 implementing the
present invention. In the network 300, a mobile unit 302
communicates with cell site equipment 304 via an RF interface. In
the illustrated example, the mobile unit 302 is shown as being a
wireless telephone. It will be appreciated, however, that any
suitable mobile unit can be utilized including, for example,
personal digital assistants, data terminals having a wireless
modem, etc. The cell site equipment 304 may be, for example, a cell
sector antenna or the like. In the illustrated network 300, the
cell site equipment 304 is interconnected to a switch 306. Although
only one piece of cell site equipment 304 is illustrated, it will
be appreciated that switch 306 may service multiple cells. The
switch 306 may be, for example, a mobile switching center (MSC) or
any other structure for routing communications between a calling
unit and a called unit. As will be discussed in more detail below,
the switch 306 may also be operative for generating billing records
such as Call Detail Records for transmission to a billing
application of a wireless carrier or other service provider.
[0039] FIG. 3 also shows a platform 308 associated with the switch
306. The platform 308 may be, for example, a computer platform for
executing a variety wireless network applications. The platform 308
may be physically located proximate to the switch 306 or may be
remotely located and interconnected to the switch 306 by a local
area network, wide area network or other communications pathway.
The illustrated platform 308 includes a microprocessor 310 for
running a boundary crossings application in accordance with the
present invention. As will be understood from the description
below, a boundary crossings application in accordance with the
present invention may be a fully self-contained application for
receiving location information, identifying a boundary crossing and
providing service information in response to the boundary crossing
in the form desired by the end user. Alternatively, a boundary
crossings application in accordance with the present invention may
function as a module to identify a boundary crossing and provide
information regarding the boundary crossing for further processing
by another application. In order to identify boundary crossings,
the boundary crossing application running on processor 310 can
access service zone information and location information. The
service zone information provides a definition of service zones for
use by the application. These definitions may be provided in any
suitable form. For example, a service zone may be defined as a set
of cell identifiers or cell sector identifiers that represent the
service zone. Alternatively, the service zone information may be
stored as a set of geographical coordinates or geographical
boundaries that define the service zone. For cell sector
implementations, such geographical information may be converted
into current network topology, e.g., cell sector identifiers, at
the time of a boundary crossing determination. It will be
appreciated that other conventions may be utilized for storing a
representation of a service zone area. In addition, it will be
appreciated that a GIS system may be utilized for inputting and
formatting the service zone information. For example, a service
provider or other person defining a service zone may wish to input
service zone boundaries relative to an address, streets or other
topological information. A GIS application, such as the MAPS
application marketed by SIGNALSOFT Corporation of Boulder, Colo.,
may be utilized to receive such inputs and convert the associated
service zone definitions into geographical information formatted
for convenient handling by the boundary crossing application. Thus,
service zone definitions may be converted from one topological
system, e.g., addresses or street boundaries, to another
topological system, e.g., geographical coordinates or cell/cell
sector identifiers.
[0040] Location information regarding the locations of mobile units
may also be stored for access by the boundary crossings
application. Depending, for example, on the nature of the location
finding technology employed, the nature of the received location
information and the route by which the information is obtained may
vary. For example, in the case of cell sector location information,
a cell sector identifier may be extracted from communications
between the mobile unit 302 and the switch 306. In the case of
handset-based location finding equipment such as GPS information,
location coordinates may be encoded into communications transmitted
from the unit 302 to the cell site equipment 304. In other cases,
raw location information may be preprocessed by a location
management program running on the platform 308. In any case, in
accordance with the present invention, location information may be
stored in location cache 314 so as to enable later use in a
boundary crossing analysis such as comparison of mobile unit
location information for a first time and a second time.
[0041] In the illustrated embodiment, the platform 308 is
illustrated as housing a service zone database 312 and a location
cache 314. Such a service zone database 312 may include service
zone definitions for one or more applications. The location cache
314 may include location information for mobile units at various
times indexed, for example, to a mobile unit identifier such as a
MIN/ESN. Although the database 312 and cache 314 are thus
illustrated as distinct elements, it will be appreciated that the
database 312 and cache 314 may utilize shared or non-dedicated
memory resources. Moreover, the database 312 and cache 314 need not
be located on the platform 308 or on the same machine as one
another, but rather, may reside at any location where the stored
information can be accessed by the boundary crossing
application.
[0042] As noted above, depending on the specific application and
other factors, the resulting service information can be transmitted
to different recipients via different pathways. For example, in the
case of the above noted rental vehicle tracking application, the
resulting service information is provided to a data terminal at a
rental company remote from the monitored mobile unit. To support
such applications, service information can be transmitted from the
illustrated platform 308 to a data network node 320 via a data
network 318 such as the Internet. In other applications, such as
re-rating for location based billing applications, the recipient of
the service information is another application such as a billing
application that is registered with the boundary crossings
application to receive service information, e.g., related to
boundary crossings. In the case of the location based billing
application, the service information may be a billing value of a
Call Detail Record (CDR). In such a case, the service information
may be transmitted to application 322 by way of the switch 306. In
other cases, such as the above noted emergency service or local
service applications, it is desirable to transmit the service
information to the monitored mobile unit 302. In such cases, the
service information may be transmitted to the unit 302 via the
switch 306 and cell site equipment 304.
[0043] The service information may be presented in various forms.
For example, service information may be transmitted to the mobile
unit 302 via a short messaging system for providing an audio
message that can be played on the unit 302. Alternatively, a text
message may be displayed on a LED display or other display of the
mobile unit 302. As previous noted, an output may be provided to an
application 322 such as a billing application by populating a field
of the CDR. In other applications, an audio, text and/or full
graphics presentation (e.g., a graphical map showing mobile unit
location) may be provided at a data network node 320. It will thus
be appreciated that the boundary crossings application may utilize
appropriate hardware, firmware and/or software for providing the
service information in the appropriate format and in accordance
with appropriate protocols. Thus, the information may be packetized
for transmission across the Internet in accordance with IP
protocols. Data may also be transmitted to the mobile unit 302
utilizing proxies, microbrowser and other elements for executing
wireless data communications protocol. Similarly, in the case of a
CDR output, the CDR may be populated in accordance with
telecommunications network protocols.
[0044] C. Process Implementation
[0045] FIG. 4 is a flowchart illustrating a process 400 for
implementing a boundary crossings application in accordance with
the present invention. The process 400 is initiated by receiving
(402) a service zone definition for the application. As noted
above, the nature of the service zones can vary from application to
application. The service zones or associated boundaries may include
political or government boundaries, street or other topological
data, geographical coordinates and associated cell sector
identifiers or other zone delineators or other geographical
information. Such information may be input using GIS application or
by other means.
[0046] The boundary crossings application further receives (404) a
monitoring request. For example, a vehicle rental company may enter
the MIN/ESN of all vehicles that are to be monitored, the
timeframes during which the vehicles are to be monitored and the
specific zones or boundaries with respect to which vehicle movement
is to be monitored. Similar types of information may be entered by
parents or government officials wishing to monitor movements of
individuals or by wireless carries or network subscribers relating
to bill zones. The boundary crossings application can then monitor
movements of the mobile unit or units of interest by receiving and
storing (406) current location information, retrieving (408) prior
location information for the mobile unit or units, and using (410)
the current and prior location information to determine whether a
service zone boundary has been crossed during the intervening time
interval. This monitoring can continue throughout a time period as
specified by a network user. With regard to the process for
monitoring location, the system user may specify a frequency for
monitoring if desired. Thus, for example, a rental car company may
request position updates every ten minutes or at some other
interval. At each such interval, the boundary crossings application
may access the most recent information available in the location
cache or may invoke the location finding equipment to obtain
current information. It will be appreciated that different
frequencies may be useful for different applications.
Alternatively, the boundary crossings application can be programmed
to make a boundary crossing determination each time new location
information is received for a mobile unit of interest. In this
regard, it will be appreciated that such location information may
be obtained as a result of a periodic polling process in connection
with normal network administration.
[0047] The process of using the current and prior location
information to identify boundary crossings may utilize the two most
recent instances of location information for a particular mobile
unit, or may utilize location information for other times.
Moreover, in certain cases, such as in the case of GPS information,
location information for a particular time may be coupled with
travel direction and speed information. Such travel direction and
speed information may also be obtained by processing location
information for a particular mobile unit at two or more times. In
such cases, tracking information may be used to identify or predict
a boundary crossing without relying on a change of status as
between first and second location information and first and second
times relative to a zone boundary. Once a determination is made
(412) as to whether a boundary crossing has occurred, the boundary
crossing application may continue monitoring mobile unit
location/movement and/or may generate (414) service information
according to application parameters. In the latter regard, the
boundary crossings application may be programmed to output a
billing parameter, retrieve and transmit prerecorded service
information, or otherwise output service information depending on
the specifics of the program. The service information is then
transmitted (416) according to application parameters. Such
application parameters may specify the recipient, content and
format of the service information as discussed above.
[0048] While various embodiments of the present invention have been
described in detail, it is apparent that further modifications and
adaptations of the invention will occur to those skilled in the
art. However, it is to be expressly understood that such
modifications and adaptations are within the spirit and scope of
the present invention.
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