U.S. patent application number 11/239790 was filed with the patent office on 2006-02-09 for enhanced pde selection.
This patent application is currently assigned to Openwave Systems Inc.. Invention is credited to Steven P. Nowak.
Application Number | 20060030337 11/239790 |
Document ID | / |
Family ID | 35758072 |
Filed Date | 2006-02-09 |
United States Patent
Application |
20060030337 |
Kind Code |
A1 |
Nowak; Steven P. |
February 9, 2006 |
Enhanced PDE selection
Abstract
A method and apparatus for managing the selection of location
information sources (e.g., position determining equipment sites and
handset-based location finding capabilities) to provide location
information for a mobile communications unit (e.g., a cellular
phone) are disclosed. Embedded within a request for location
information on a particular mobile communications unit are one or
more specifications regarding the quality of the requested location
information. Such specifications is used to determine if any
location information sources are able to provide the location
information with the desired location information quality. Upon
locating a location information source capable of providing the
requested location information, the source is invoked to provide
the particular location information. Once the location information
is provided by the location information source, it is provided to
the requesting party.
Inventors: |
Nowak; Steven P.; (Superior,
CO) |
Correspondence
Address: |
TOWNSEND AND TOWNSEND AND CREW/22395
TWO EMBARCADERO CENTER
EIGHTH FLOOR
SAN FRANCISCO
CA
94111-3834
US
|
Assignee: |
Openwave Systems Inc.
Redwood City
CA
|
Family ID: |
35758072 |
Appl. No.: |
11/239790 |
Filed: |
September 29, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10071117 |
Feb 7, 2002 |
6968195 |
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11239790 |
Sep 29, 2005 |
|
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09796972 |
Mar 1, 2001 |
6757545 |
|
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10071117 |
Feb 7, 2002 |
|
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Current U.S.
Class: |
455/456.2 |
Current CPC
Class: |
H04W 4/90 20180201; H04W
8/18 20130101; H04W 64/00 20130101; H04W 76/50 20180201 |
Class at
Publication: |
455/456.2 |
International
Class: |
H04Q 7/20 20060101
H04Q007/20 |
Claims
1. A method for use in providing location information regarding
mobile units in a mobile communications system, said method
comprising the steps of: receiving a request for location
information for a first Mobile unit, said request identifying said
first mobile unit and further including at least a first
specification regarding a quality of said requested location
information; based on said first specification, selecting at least
one location information source capable of providing responsive
location information for said first mobile unit; obtaining said
responsive location information from said selected location
information source, wherein said responsive information at least
substantially conforms to said first specification regarding said
quality of said requested location information; and providing said
responsive location information to a selected location based on
said request.
2. The method of claim 1, further comprising the steps of:
receiving a first indication of the general location of said first
mobile unit; and using said general location of said first mobile
unit in said selecting step to identify location information
sources in a proximity of said mobile unit such that one of said
identified location information sources may provide said responsive
location information.
3. The method of claim 2, wherein said first indication of the
general location of said mobile unit is a standard identifier
utilized by said mobile communications system.
4. The method of claim 3, wherein said standard identifier
comprises at least one of a cell identifier and a cell sector
identifier utilized by said mobile communications system.
5. The method of claim 1, wherein said step of selecting further
comprises selecting at least one location information source from a
plurality of location information sources operable to provide said
responsive location information.
6. The method of claim 5, wherein said plurality of location
information sources comprises one of a database containing
responsive location information and equipment associated with the
mobile communications system operable to obtain responsive location
information.
7. The method of claim 5, wherein said step of selecting further
comprises utilizing a default specification to select between
multiple acceptable location sources, where each of said multiple
acceptable location sources is capable of obtaining location
information at least substantially conforming to said first
specification.
8. The method of claim 1, wherein said step of obtaining further
comprises invoking said selected location information source to
provide said responsive location information.
9. The method of claim 1, wherein said specification establishes a
priority for selecting said location information source to provide
responsive location information for a particular request.
10. The method of claim 9, wherein said priority is established by
a last in first out command.
11. The method of claim 1, wherein said specification specifies a
particular type of location information source for use in providing
said responsive location information.
12. The method of claim 1, wherein said specification regarding a
quality of said requested location information is related to a
geographical accuracy for said responsive location information.
13. The method of claim 1, wherein said specification regarding a
quality of said requested location information is related to an
acceptable cost associated with said responsive location
information.
14. The method of claim 1, wherein said specification regarding a
quality of said requested location information is related to an
allowable age of said responsive location information.
15. The method of claim 1, wherein said specification regarding a
quality of said requested location information is related to
acceptable response times to provide said responsive location
information.
16. The method of claim 1, wherein said receiving step further
comprises correlating said specification to a corresponding value
associated with said location information sources.
17. The method of claim 16, wherein said correlating step involves
correlating said specification to an average value associated a
plurality of location information sources.
18. The method of claim 16, wherein said correlating step involves
correlating said specification to a first value associated with an
individual location information source.
19. The method of claim 1, wherein said selecting step comprises
consulting at least a first database in which information
associated with said location information sources is stored.
20. The method of claim 1, wherein said selecting step further
comprises consulting at least a first database in which information
regarding location determining abilities of said position location
information sources are stored such that only location information
sources capable of providing said responsive location information
are selected.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 10/071,117, entitled "Enhanced PDE Selection,"
filed on Feb. 7, 2002; which is a continuation in part of U.S.
patent application Ser. No. 09/796,972, entitled "Location
Information Management System and Method for Mobile Communications
Unit," filed on Mar. 1, 2001, which is now U.S. Pat. No. 6,757,545,
the entire disclosures of which are incorporated by reference
herein in their entirety.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] The present invention generally relates to the use of
position determination equipment (PDE) in relation to a mobile
communications system (e.g., a wireless network) and, more
particularly, to selecting a PDE according to specifications in a
location information request for a mobile communications unit.
[0004] Wireless communications networks generally allow for voice
and/or data communication between wireless stations, e.g., wireless
telephones (analog, digital cellular and PCS), pagers or data
terminals that communicate using RF signals. In recent years, a
number of location based service systems have been implemented or
proposed for wireless networks. Such systems generally involve
determining location information for a wireless station and
processing the location information to provide an output desired
for a particular application.
[0005] Examples of such existing or proposed applications include
emergency or "911" applications, location dependent call billing,
cell-to-cell handoff and vehicle tracking. In 911 applications, the
location of a wireless station is determined when the station is
used to place an emergency call. The location is then used to route
the call and, perhaps, is transmitted to a local emergency
dispatcher to assist in responding to the call. In typical location
dependent call billing applications, the location of a wireless
station is determined, for example, upon placing or receiving a
call. This location is then transmitted to a billing system that
determines an appropriate billing value based on the location of
the wireless station. In handoff applications, mobile unit location
is determined in order to coordinate handoff of call handling
between network cells. Vehicle tracking applications are used, for
example, to track the location of stolen vehicles. In this regard,
the location of a car phone or the like in a stolen vehicle can be
transmitted to the appropriate authorities to assist in recovering
the vehicle.
[0006] From the foregoing, it will be appreciated that location
based service systems involve position determination equipment
(PDE) and location-related applications. To some extent, the PDEs
and applications have developed independently. In this regard, a
number of types of PDEs exist and/or are in development. These
include so-called angle of arrival (AOA), time difference of
arrival (TDOA), handset global positioning system (GPS) and the use
of cell/sector location. The types of equipment employed and the
nature of the information received from such equipment vary in a
number of ways. First, some of these equipment types, like GPS, are
generally wireless station-based whereas others are "ground-based,"
usually infrastructure-based. Some can determine a wireless
station's location at any time via a polling process, some require
that the station be transmitting on the reverse traffic channel
(voice channel), and others can only determine location at call
origination, termination, and perhaps registration. Moreover, the
accuracy with which location can be determined varies significantly
from case to case. Accordingly, the outputs from the various PDEs
vary in a number of ways including data format, accuracy and
timeliness.
[0007] The nature of the information desired for particular
applications also varies. For example, for certain applications
such as 911, accuracy and timeliness are important. For the
applications such as vehicle tracking, continuous or frequent
monitoring independent of call placement is a significant
consideration. For other applications, such as call billing,
location determination at call initiation and call termination or
during handoff is generally sufficient.
[0008] Heretofore, an incoming position request has only been able
to limit the location information provided by the PDEs to a maximum
allowable uncertainty and/or location information no older than a
specified value. This has not always resulted in the most efficient
use of PDEs in a mobile communications system or resulted in the
best use of available resources for a particular wireless location
application. For example, some applications such as 911 may
desire/require the most current location information with the
highest level of geographical accuracy. In contrast, the needs of
other applications such as a fleet tracking system may be met by
using less current and/or less geographically accurate location
information.
SUMMARY OF THE INVENTION
[0009] The present invention provides a method and apparatus for
use in a mobile communications location information management
system to select at least a first position determining equipment
source to provide location information regarding a mobile
communications unit such as a cell phone in a mobile communications
system. More particularly, the method provides for selecting a
position determining equipment (hereinafter "PDE") source from a
plurality of PDE sources that are capable of providing location
information. The method comprises the steps of: receiving a request
for location information for the desired mobile communications
unit, where the request includes at least one specification
regarding the location information; selecting one PDE source from
the plurality of PDE sources based on the specifications; obtaining
location information from that PDE source for the desired mobile
communications unit (hereinafter "MCU"); and directing the location
information to a location associated with the request (e.g., the
requesting parties). The corresponding apparatus of the present
invention includes ports for communicating with the requesting
party and PDE sources (or a source gateway) and a processor for
implementing PDE selection logic as described below. The invention
allows a requesting party to request location information that is
specifically tailored to its needs, for example, a requesting party
which requires highly accurate geographical information, such as
911 services, are able to request location information from the PDE
sources with the highest "granularity" (i.e., highest resolution)
in the system. In contrast, requesting parties with lower quality
needs may be able to request location information that has less
geographical granularity, which may be older and have a lower cost
to the requesting party. Alternatively, in the case where multiple
sources of sufficient information are available, a PDE source may
be selected on other bases.
[0010] The request will generally contain a number of fields that
correspond to various prerequisites and requirements for location
information. In particular, the request will generally contain some
sort of identifier such that the MCU to which the location
information request is being made may be identified. Additional
fields may be provided such that in accordance with the present
invention, the request may include one or more requirements or
prerequisites related to the desired location information. This may
be characterized as a "quality of service" (QoS) parameter and the
interactive process between the requesting party and a Location
Information Management System for QoS determination may be deemed a
QoS negotiation. Each of these QoS parameters may be evaluated
individually or in combination to determine if any PDE sources will
be able to provide location information for the MCU in accordance
with these parameters. Additionally, some of these QoS parameters
may be specified relative to predefined ranges. For example, a
client may be able to request location information for a particular
MCU where that information has an accuracy or uncertainty within a
specified range. Prior to the request, the client application may
know the accuracies associated with each range category. The client
may know, for example, that it can request low, medium or high
accuracy location information which corresponds to, for example, an
accuracy or uncertainty of 700 meters, accuracy between 300 and 700
meters, and accuracy less than 300 meters, respectively. However,
it will be appreciated that any number of value ranges, such as
ranges 1-N, may be used and that each range may be assigned
different accuracy values.
[0011] The QoS parameters that may be specified in the request may,
in addition or as an alternative to geographical accuracies,
include other specifications. These specifications may include
designation of an acceptable level of cost associated with the
location information, requirements to an acceptable range of ages
for the location information and/or a requirement related to a
range of acceptable response times to receive the location
information. With respect to the cost requirement, the request may
be made such that location information up to, but not more than, a
certain cost is authorized. With respect to the allowable range of
age for the location information, it will be appreciated that,
often, some sort of location information is available without
requesting a new PDE source to initiate location sequence. For
example, if an MCU has been located recently, that information may
be stored in one or more databases within a mobile communications
system. In this instance, the database may be considered a PDE
source. Therefore, in some instances, it is possible to retrieve
location information without utilizing PDE sources that require a
network location search. However, this information may be outdated
for some purposes. In this regard, the specification of the
allowable age of the requested location information may specify
that the location information may not be older than a certain age.
Again, this allows location-based applications to specifically
tailor the requested location information to their needs. Likewise,
the acceptable response time may be defined in a range of values
such that time dependent applications, such as 911, may request
location information with response time less than X. In this
instance, the Location Information Management System may operate
such that it provides the best location information available at
the end of the specified response time. For example, if the
response time is not greater than a specified time and the only
information that the Location Information Management System can
provide in that time is cell/sector location information, then
cell/sector location will be provided.
[0012] In addition or in alternative to specifications that allow a
user to specify a range of limitations related to location
information, the specification in the request may include
instructions on how the Location Information Management System is
to operate. For example, the requirement may have a priority field
that determines how the Location Information Management System will
process the request. For example, in the case of emergency service
such as 911, there may be a field in the request that specifies
highest priority. This highest priority could be a last in, first
out command which instructs the Location Information Management
System to process the request as soon as it is received, in front
of other requests in the queue, thus altering the general first in,
first out operation of the system. Another requirement that may be
utilized with this present invention is a specification for the
Location Information Management System to use a particular type of
position determining equipment source to provide the desired
location information. For example, a requesting party may specify
that the location information is to come from a TDOA PDE source in
the network or, alternatively, it may specify for a particular
geographically situated PDE site to provide the location
information.
[0013] The step of receiving may further involve processing the
specification information of the various fields of the location
information request for use with the Location Information
Management System. For example, a specification within the request
may have to be correlated with values relating to certain aspects
related to the PDE sources. For instance, where the Location
Information Management System operates with a PDE carrier system
which employs three different types of PDE sources (e.g.,
cell/sector, TDOA, AGPS) which provide varying accuracies of
location information, a geographical specification in the request
(e.g., low, medium, high) may be correlated to a particular type of
PDE sources (low=cell/sector, medium=TDOA, high=AGPS). As will be
appreciated, the various requirements in the location information
request may be correlated with various PDE source variables that
correspond with the requirements. Further, the requesting party may
know the general range of what they are requesting, however, they
may not know how the Location Information Management System
correlates their request to the PDE sources. For example, in one
embodiment, the Location Information Management System may
correlate the specifications in the request to individual PDE
sources in the mobile network or to hybrid information obtained by
combining information obtained from multiple sources. In this case,
the Location Information Management System may consult a database
in which information regarding the determining abilities of the PDE
sources is stored. After consulting this database, the Location
Information Management System may correlate the requirements in the
request to the individual PDE sources or hybrid information.
Alternatively, the Location Information Management System may
correlate the requirements in the request to average values within
the PDE source network. For example, in a network using three types
of PDE sources, the average accuracy values of each of these
sources may be stored in, for example, a database record providing
an average value for each source relating to each QoS parameter
that may be specified in a request. In this regard, it will be
appreciated that information from a particular source, such as
TDOA, may be provisioned by multiple sites having varying
accuracies.
[0014] Once the requirements within the location information
request have been correlated to PDE values, the Location
Information Management System can select a PDE source to provide
the desired location information. Generally, the determination of
which PDE source, if any, would be able to provide location
information on an MCU in accordance with the requirements in the
location information request may entail consulting a database or
other appropriate data storage structure having information on
these PDE sources. Various types of information may be stored on
each PDE source or on the average capabilities of the multiple PDE
sources within a given PDE network. Typically, the information will
include an identifier that is unique to each particular PDE source
or type of PDE in the network, followed by other information
relating to the PDE sources' characteristics, which may be
correlated with various QoS parameters. For example, a geographical
description of the coverage area may be defined for each PDE
source, the response time for each PDE source, costs associated
with each PDE source, whether the PDE source works with handset
based location finding technologies, etc. The Location Information
Management System of the present invention will then begin to
eliminate those PDE sources that do not comply with the
requirements of the location information request or otherwise
identify any suitable PDE or PDEs. For example, if the request
indicates that location information must be obtained with a cost of
no more than X, all the PDE sources with a cost basis higher than X
will be eliminated from consideration. Thus, if a particular PDE
source cannot provide location information on a particular MCU with
the required QoS parameters, this particular PDE source will not be
considered to provide location information. Though discussed in
reference to eliminating PDE sources from consideration, the
present invention may also be utilized to affirmatively select only
those PDE sources that meet the QoS parameters for
consideration.
[0015] With regard to the selection process, there is an important
distinction as to if or when a general location of the MCU is
known. In the case where a location information request contains a
general location of the MCU for which information is desired or
such general location is otherwise available, the Location
Information Management System may be able to select individual
sites of a PDE source. In this case, the Location Information
Management System may consult a database record using the general
location information to determine individual PDE sources able to
provide location information for part of or, preferably, all of the
general location where the MCU unit is located. Once this is
completed, a list of PDE sources able to provide location
information for the general location of the MCU is provided.
Typically, this list will contain a PDE source identifier that may
be used to search another database or relational database table
such that the individual characteristics (which may be correlated
with QoS parameters) of the PDE sources may be determined. Again,
the Location Information Management System may compare the
correlated requirements from the location information request to
the corresponding parameters within the PDE source records,
eliminating those that cannot provide location information within
the specified parameters.
[0016] Information may also be stored on one or more, and
preferably each of, the mobile communications units that are part
of the mobile communications network. A database or database
structure may be used for this purpose as well. Information that
may be stored on a mobile communications unit specific basis and
that may be useful in implementing the first aspect is whether or
not a particular mobile communications unit has handset-based
location finding capabilities, such as GPS. The first aspect of the
invention could then be adapted to first determine if the mobile
communications unit for which location information is desired has
handset-based location finding capabilities, and to consult the
cell/position determination equipment site database only if the
mobile communications unit of interest does not have handset-based
location finding capabilities. This protocol could be reversed
whereby the handset-based location finding capabilities of the
subject mobile communications unit would only be evaluated if the
determination of the general location of the subject mobile
communications unit first led to a determination that no position
determination equipment site was available for providing the
desired location information.
[0017] Location information on a mobile communications unit may be
requested by one or more location-based systems or applications.
Requests for location information may be directed to a location
information management system or location manager which executes
the functionality of the subject first aspect. Although the
location-based applications may be part of or interface with the
mobile communications system in at least some manner, the first
aspect contemplates that these location-based applications may be
in direct communication with this location information management
system as well. That is, any way of operatively interconnecting the
location information management system and these location-based
applications may be utilized in relation to the subject first
aspect. In any case, the request for location information on a
particular mobile communications unit will be relayed by the
location information management system to one or more position
determination equipment sites only if the location information
management system associated with the first aspect first determines
that each such position determination equipment site will be able
to actually provide the desired location information. That is, the
location information management system associated with the first
aspect will not invoke a request for location information to a
particular position determination equipment site unless the
location information management system first determines that the
position determination equipment site will be able to provide the
desired location information on the subject mobile communications
unit. Consider the case where there are first, second, and third
position determination equipment sites, and where the mobile
communications unit is physically located within the coverage area
of only the first position determination equipment site. In
accordance with the foregoing, a request for location information
will be invoked only in relation to the first position
determination equipment site and not the second or third position
determination equipment sites. Related to the foregoing, any
location information management system associated with the first
aspect of the present invention may be configured so as to invoke a
request to a particular mobile communications unit for
handset-based location information only if any such location
information management system first determines that this particular
mobile communications unit does indeed have handset-based location
finding capabilities.
[0018] The request for location information on a particular mobile
communications unit in association with the first aspect may
include one or more requirements or prerequisites relating to the
desired location information. This may be characterized as a
"quality of service negotiation." Each of these requirements may be
evaluated in accordance with the subject first aspect of the
present invention in relation to determining if any of the position
determination equipment sites will be able to provide the location
information on the mobile communications unit in accordance with
the specified requirements. For instance, the request may include a
time limit for receiving the location information on a given mobile
communications unit. If a particular position determination
equipment site cannot make the location determination within this
time limit, a request for location information will not be invoked
to this particular position determination equipment site. An
acceptable uncertainty associated with the location information may
also be included with a request for location information. For
instance, a particular request may provide that the location
information must be within +.+-.10 feet. If a particular position
determination equipment site cannot provide location information on
a particular mobile communications unit with this degree of
accuracy, a request for location information on the particular
mobile communications unit will not be invoked to this particular
position determination equipment site. Another requirement which
may be provided along with a request for location information on a
particular mobile communications unit is an acceptable cost or
price for receiving this location information, and including in the
form of a "not to exceed" amount which is specified. If a
particular position determination equipment site cannot provide
location information on the particular mobile communications unit
within the financial constraints imposed by the request, a request
for location information on this mobile communications unit will
not be invoked to this particular position determination equipment
site. Another factor that may be specified in relation to a request
for location information is the "age" of the location information.
In this case, the first aspect may utilize a database of the like
which stores the last known location of at least one of, and more
preferably each of, the mobile communications units that are part
of the mobile communications network. The first aspect may then be
adapted to first consult this information source to determine if
the location information that is stored on the mobile
communications unit at issue satisfies the corresponding request,
and to thereafter proceed with a handset-based position
determination evaluation or other position determination equipment
site (e.g., network-based) evaluation only if the most recent and
stored location information does not satisfy the outstanding
request.
[0019] In the situation where the general location of the mobile
communications unit is not provided, the Location Information
Management System may use network-based averages to select a PDE
type that may be used to provide location information. In this
regard, information regarding each type of PDE available (AOA,
TDOA, AGPS, etc.) may be stored as a record in a database and
contain a listing of the average values for each of the
characteristics associated with the PDE sources. For example, it
may be known that AOA systems within the PDE source network
provide, on average, location information within X meters of the
MCU location with a response time of Y and a cost of Z. Therefore,
when the general location information of the MCU is not included in
the request, the Location Information Management System may select
a type of PDE source from the database record which have network
average values that correspond with the requirements of the
location information request. The Location Information Management
System may then send a request to another platform in the mobile
communications network to provide the location information from the
selected type of PDE, as will be more fully discussed below.
[0020] Often, only one PDE source will be able to provide the
location information requested in accordance with the requirements
in a location information request. This is especially likely when
there are multiple requirements within the request. However, in
some cases, multiple PDE sources may be determined to be available
or appropriate for providing location information on a particular
MCU (i.e., multiple PDE sources satisfy all the requirements
associated with the request for location information on a
particular MCU). This may occur, for example, where the only
requirement is location information with a cost less than X. In
this instance it may still be desirable to only receive location
information from a single source; therefore, the remaining PDE
sources may be further limited, using some secondary consideration.
For example, the first PDE source on the list may be chosen or some
secondary QoS specification, such as speed of processing, may be
chosen as a default to further limit the number of PDE sources
until only one remains. Alternatively, there may be a client
profile database that specifies a particular client's preferences
as to secondary considerations.
[0021] Alternatively or additionally, such PDE selection may be
based at least in part on a business rule set. In this regard, a
set of rules or an algorithm may be provided for a particular
operator, application or the like. For example, the algorithm may
specify that, if a particular PDE source is available for the
subscriber and/or network area, then that PDE should be utilized.
The algorithm may further specify that if the first preferred
source is not available then a second identified source should be
used if available and so on. Similarly, a location based billing
application may specify that Cell ID information should be used for
ongoing monitoring of a subscriber's location until Cell ID
information becomes inadequate to determine whether, for example,
the subscriber is inside or outside of a "home zone." More complex
algorithms could specify different sources, accuracies, timeliness,
etc. under different conditions or at different times. Such
algorithms could be executed by an application or in connection
with a gateway or other location platform. In the context of a
defined interface for requesting location information, the
algorithm could instruct the location platform to ignore attributes
specified in the location request or the algorithm could be applied
with respect to attributes not populated.
[0022] The step of obtaining location information from the selected
PDE source may vary depending on what information was used to
select the PDE source. In the case where the general location
information of the MCU was known, individual PDE sources may have
been identified such that a request may be sent directly to such
sources for the location information. In contrast, where the
general location of the MCU was not known during the selection
process, a request may be sent to a platform within the PDE network
requesting a certain type of PDE source be used to provide the
information. In this case, the PDE network may determine which
individual source is in the proximity of and able to provide
location information for the MCU, e.g., based on separately
obtained general location information, e.g., cell or cell sector
information. As will be appreciated, the PDE network is generally
in communication with the mobile communications network. As such,
the PDE network may have the ability to determine a general
location of the MCU within the mobile network. For example, when
the MCU is being powered or is in an "on" condition, one or more
signals will be exchanged on some basis (e.g., intermittently,
periodically) between the MCU and cell site equipment in the area
in which the MCU is then physically located. This information may
be stored, for example, in a home location register ("HLR"),
visitor location register ("VLR") or some other storage means
within the network. The PDE network in this case will determine the
general location of the MCU and invoke the proper PDE source in
proximity of the MCU to provide location. In either case, once the
location information is determined by the PDE source, it is
returned to the Location Information Management System where it may
then be returned to a party associated with the incoming request or
other designated location. For example, the incoming request may
provide instructions on where the location information is to be
sent or the location information may be sent directly back to where
the location information request originated from.
[0023] Finally, in the case where no PDE sources are able to
provide location information in accordance with the specifications
in the request, the Location Information Management System may be
configured to return some sort of error message indicating that the
system is unable to provide the location information to the desired
specifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a schematic representation of an embodiment of a
mobile communications system which includes or which interfaces
with a location information management system in accordance with
the present invention;
[0025] FIG. 2 is one embodiment of a cell/sector structure that may
be utilized by the mobile communications system of FIG. 1;
[0026] FIG. 3 is a schematic representation of the location
information management system of FIG. 1;
[0027] FIG. 4 illustrates an embodiment of a position determination
equipment site database structure that may be utilized by the
location information management system of FIG. 1;
[0028] FIG. 5 illustrates an embodiment of a cell/position
determination equipment site database structure that may be
utilized by the location information management system of FIG.
1;
[0029] FIG. 6 illustrates an embodiment of a home location register
database structure that may be utilized by the location information
management system of FIG. 1;
[0030] FIG. 7 illustrates an embodiment of a system/position
determination equipment capabilities database structure that may be
utilized by the location information management system of FIG. 1;
and
[0031] FIG. 8 illustrates an embodiment of a location information
management protocol that may be utilized by the location
information management system of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0032] One embodiment of a mobile or wireless communications
network or system 10 is presented in FIG. 1. The mobile
communications system 10 includes at least one Mobile
Communications Unit 14 (e.g., a cellular phone) which communicates
with a cell site equipment system 18 by an appropriate
communications link 30a i.e., an RF link. A portion of this cell
site equipment system 18 together with associated coverage areas is
illustrated in FIG. 2. The cell site equipment system 18 of FIG. 2
includes a plurality of cells 22a-h. Each cell 22a-h includes a
plurality of cell sectors 26a-c. Each cell 22a-h and its various
cell sectors 26a-c cover a certain geographical area. At least one
transmitter and at least one receiver (or a "transceiver"), as well
as at least one antenna (all not shown), are associated with each
cell sector 26a-c for handling all communications involving any
Mobile Communications Unit 14 that is physically located within or
possibly in proximity to the particular cell sector 26. Typically a
single directional antenna will be utilized by each cell sector 26
in the type of configuration presented in FIG. 2, and the coverage
area of the antennas in a given cell 22 will overlap to a degree.
Although each of the cells 22 and cell sectors 26 are illustrated
in FIG. 2 as being of the same size and configuration, such need
not be the case in relation to the functionality of a Location
Information Management System 58 which is part of or at least
operatively interfaces with the mobile communications system 10,
and which is discussed in more detail below. Moreover, adjacent
cells 22 may be disposed in overlapping relation without adversely
affecting the functionality of the Location Information Management
System 58.
[0033] An appropriate communications link 30b operatively
interconnects the cell site equipment system 58 with a mobile
switching center 34 as illustrated in FIG. 1. The mobile switching
center 34 in turn is operatively interconnected with a
communications linking system 38 (e.g., a telephone company central
office, one or more central switching offices) by an appropriate
communications link 30c. Communications involving the Mobile
Communications Unit 14 are thereby directed through the cell site
equipment system 18, the mobile switching center 34, and
communications linking system 38 to the other device(s) involved in
the subject communication. Any way of providing communication
capabilities between a given Mobile Communications Unit 14 and
another communication device may be employed without adversely
affecting the functionality of the Location Information Management
System 58.
[0034] The Location Information Management System 58 may be
directly operatively interconnected with the mobile switching
center 34 by an appropriate communications link 30d, and may be
directly operatively interconnected with the cell site equipment
system 18 by an appropriate communications link 30g (as indicated
by the dashed line in FIG. 1), or both. Any way of integrating the
Location Information Management System 58 with the mobile
communications network or system 10 may be utilized, including such
that the Location Information Management System 58 is part of the
system 10 or separate therefrom. Multiple components are part of or
interface with the Location Information Management System 58 in
relation to communications involving any Mobile Communications Unit
14 of the mobile communications system 10 (e.g., communications
being directed through the mobile switching center 34). These
components may either be part of or separate from the mobile
communications system 10. One such component is a position
determination equipment system 46 that is operatively
interconnected with the Location Information Management System 58
by an appropriate communications link 30e. The PDE system 46
generally provides a source to determine the location of a
particular Mobile Communications Unit 14. In this regard, the
illustrated PDE system 46 generally includes a plurality of PDE
sites 50a-c that may be located at various physical locations
throughout the mobile communications system 10. Any technology
which is appropriate for determining the location of a given Mobile
Communications Unit 14 may be employed at any given PDE site 50. As
used herein, a PDE source is used to discuss any source able to
provide location information, such as a database and/or PDE sites
50, whereas a PDE site 50 generally entails a fixed network
structure for providing location information. Representative
examples of position determination technologies which are
appropriate for the position determination equipment system 46
include GPS-based technologies, cell sector or micro-cell location
technologies, time difference of arrival (TDOA) technologies, angle
of arrival (AOA) or other network triangulation technologies, and
enhanced observed time difference (EOTD), and TOA or network
assisted GPS. It will be appreciated that these technologies may be
handset based, network based or network overlay technologies.
[0035] The illustrated position determining system includes sites
50a, 50b and 50c, may operate separate from the MSC 34 and may
include network based systems, (e.g., AOA and TDOA systems), and
external systems such as GPS. Generally, the illustrated network
based system such as AOA and TDOA systems determine the location of
a Mobile Communications Unit 14 based on communications between the
Mobile Communications Unit 14 and the cell site equipment system
18. For example, such systems may receive information concerning a
directional bearing of the Mobile Communications Unit 14 or a
distance of the Mobile Communications Unit 14 relative to each of
multiple cell sites 22 or other sites. Based on such information,
the location of the Mobile Communications Unit 14 can be determined
by triangulation or similar geometric/mathematic techniques.
External systems such as GPS systems, determine the Mobile
Communications Unit's location relative to an external system. In
the case of GPS systems, the Mobile Communications Unit 14 is
typically provided with a GPS receiver for determining geographic
position relative to the GPS satellite constellation. This location
information is then transmitted across an air interface to the
network 10.
[0036] As noted, the network 10 further includes a cell site
equipment system 18 for communicating with the Mobile
Communications Unit 14. In this regard, the cell site equipment
system 18 may include three or more directional antennas for
communicating with Mobile Communications Units within subsections
of the cell area. These directional antennas can be used to
identify the subsection of a cell where the Mobile Communications
Unit 14 is located. In addition, ranging information obtained from
signal timing information may be obtained to identify a radius
range from the cell site equipment where the Mobile Communications
Unit 14 is located, thereby yielding a Mobile Communications Unit
14 location in terms of a range of angles and a range of radii
relative to the cell site equipment. This cell/sector location
information can be transmitted to the Location Information
Management System 58 via an appropriate communications link.
Therefore, the cell site equipment system 18 may also be
characterized as a PDE source. Additionally, inputs from multiple
sources may be combined to yield location information as described
in U.S. Pat. No. 6,321,092, which is incorporated herein by
reference.
[0037] Another component that is operatively interconnected with
the Location Information Management System 58 by an appropriate
communications link 30f is one or more location based applications
54. Location information regarding a particular Mobile
Communications Unit 14 may be desired or required by each of these
location based applications 54. Requests for location information
from any of the location based applications 54 are managed by the
Location Information Management System 58. Although the mobile
communications system 10 has been described in accordance with the
foregoing structure, the functionality of the Location Information
Management System 58 may be integrated in the mobile communications
system 10 in any appropriate manner. For instance, the Location
Information Management System 58 may be readily adapted for any way
of routing mobile or cellular communications without affecting
operation of the present invention. As shown in FIG. 3 the
location-based applications 54 are interconnected to the Location
Information Management System 58 through an interface 60. The
interface 60 allows location-based applications 54 to selectively
access or request information from the Location Information
Management System 58. The interface 60 provides a standardized
format for submitting location requests to the Location Information
Management System 58. This format may include a number of defined
fields as will be discussed in more detail below. In this manner,
the applications 54 can make use of the best or most appropriate
location information available from any PDE source without concern
for PDE-dependent data formats or compatibility issues. Moreover,
new position-determining technologies can be readily incorporated
into the wireless system 10 and used by the applications 54 without
significant accommodations for the existing applications 54, as
long as provision is made for providing data to the Location
Information Management System 58 in a standardized format.
[0038] The interface 60 allows the applications 54 to include in a
location request for a particular Mobile Communications Unit 14,
one or more specifications or "Quality of Service" (QoS) parameters
in one or more fields regarding desired location information. These
QoS parameters are related to the information provided by various
PDE sites 50 in the mobile communication system 10. The PDEs 50a-c
may provide location information in various forms; therefore, the
illustrated Location Information Management System 58 is capable of
correlating the QoS parameter from the fields of the request with
the location information provided by a particular PDE site 50, as
will be more fully discussed below.
[0039] The interface 60 allows the location-based applications 54
to include at least a first QoS parameter with a request regarding
the location information for the desired Mobile Communications Unit
14. For example, the QoS parameter may include one or more of the
following: maximum allowable age of the location information, the
geographical accuracy of the information, the cost of the
information, response time required to produce the information,
priority of processing for the information, and even specifying
which type of PDE source will provide the information. More
particularly, in accordance with the present invention, some of the
QoS parameters and, in particular, geographical accuracy, cost, and
response time may be divided into a selectable range of values that
will be used by the Location Information Management System 58 to
select a PDE source or site and provide location information. This
enables the Location Information Management System 58 to provide
location information regarding a particular Mobile Communications
Unit 14 specifically `tailored` to a location based application's
request and thus eliminate unnecessary invocations of PDE sources.
For example, when the QoS parameter within the location based
application's request is directed to geographical accuracy of the
information, the parameter may be sub-divided into a range of
values relating to geographical accuracy such as low, medium and
high or, alternatively, any number of accuracy ranges 1-n. These
parameter values may then be used by the Location Information
Management System 58 to limit selection of PDE sites 50 to those
sites that are able to provide information in accordance with the
specified parameters of the location information request.
[0040] The interface may be configured to translate the specified
range to a numerical or other convenient value for comparison with
attributes in the PDE database record. This configuration makes it
possible to revise the range of the specification as system
capabilities increase. For example, as improvements to geographical
accuracy within the system become available, the interface may be
configured such that it is able to receive requests from a client
(i.e., application) having a narrower range. In this instance,
instead of having low, medium and high geographical accuracy value,
it may be possible to have divisions of 1-10. As the granularity of
the requirements in the requests increase, the Location Information
Management System 58 may be configured to combine or aggregate the
abilities of one or more PDE sites 50 to provide location
information having a specified parameter. For example, it may be
possible to use two or more PDE sites 50 involving the same or
different technologies where neither site contains the specified
geographical accuracy or where one or more of the sites provides
incomplete information and invoke the combination of the two or
more PDE sites 50 to produce the desired geographical accuracy.
Thus, where a handset does not have contact with the required
number of satellites to provide complete GPS information, partial
GPS information may be combined with other location information,
e.g., cell sector information, to yield the desired location
information.
[0041] Where a gross or general location of a Mobile Communications
Unit is provided with a location request or otherwise available,
the Location Information Management System 58 is operable to
identify each PDE site 50 operable to provide location information
for that general location. For example, when the cell 22 or cell
sector 26 location of a unit 14 is provided or otherwise available,
the Location Information Management System 58 may associate such
cells 22 and/or cell sectors 26 with those PDE sites 50 that are
able to provide location information for units in this particular
cell 22 and/or cell sector 26. FIG. 4 presents one embodiment of a
PDE site database 62 which may be utilized by the Location
Information Management System 58 to determine which PDE sites can
provide location information for a particular Mobile Communications
Unit 14. The database 62 may reside on an appropriate
computer-readable storage medium. The PDE site database 62 may be
generally viewed as containing a database record 66 for each PDE
site 50 utilized by the Location Information Management System 58.
Each record 66 may include some or all of the following types of
information regarding various QoS parameters, each of which defines
its own separate database field: 1) a PDE site field 70 for storing
information which identifies and is unique to the subject PDE site
50; 2) a position determination technology type field 74 for
storing information which identifies the type of technology which
is utilized by the subject PDE site 50 to provide location
information on a Mobile Communications Unit 14; 3) a physical
location field 78 for storing information on the physical location
of the subject PDE site 50; 4) a coverage area field 82 for storing
information that defines the geographical area for which the
subject PDE site 50 is able to provide location information on
Mobile Communications Units 14 (alone or possibly in combination
with information in the corresponding physical location field 78);
5) a position determination accuracy field 86 for storing
information which quantifies the accuracy or uncertainty associated
with location information on a Mobile Communications Unit 14 which
is provided by the subject PDE site 50 or otherwise known; 6) a
computational speed field 90 for storing information which
quantifies the amount of time required by the subject PDE site 50
to provide location information for a Mobile Communications Unit
14; and 7) a computational cost field 94 for storing information
which quantifies the cost for providing location information on a
Mobile Communications Unit 14 utilizing the subject PDE site 50.
Moreover, other types of information and/or additional QoS
parameters may be stored in relation to each PDE site 50, and may
then be made available to the Location Information Management
System 58. For example, a field may be included which identifies if
the PDE site 50 relies upon handset based location technology. As
will be appreciated, each record 66 may also contain a blank field
98 such that future modifications to the system may be
accommodated. With regard to the coverage area field 82,
information contained therein may geographically define the
coverage area of the associated PDE site 50. Alternatively, some
type of function or parameter may be stored in the coverage area
field 82 and which defines the coverage area for the subject PDE
site 50 (e.g., information in the coverage area field 82 may be a
radius, which when combined with information in the physical
location field 78, may be used to define the coverage area of the
subject PDE site 50 through an equation for the area of a circle).
It will be appreciated that any way of storing the type of
information set forth in the PDE site database 62 may be utilized
by the Location Information Management System 58. In any case, once
the Location Information Management System 58 determines or
otherwise receives general location information on a particular
Mobile Communications Unit 14 in a manner to be discussed in more
detail below, the Location Information Management System 58 may
consult the PDE site database 62 to determine if any of the PDE
sites 50 stored therein would be able to provide location
information on the particular Mobile Communications Unit 14.
[0042] FIG. 5 presents an embodiment of a cell/PDE site database 72
which may be utilized by the location information system 58 when a
general location of a Mobile Communications Unit 14 is known to
determine if location information may be provided on a particular
Mobile Communications Unit 14, and which would typically reside on
an appropriate computer-readable storage medium. The illustrated
cell/PDE site database 72 contains a database record 75 for each
cell 22 and/or cell sector 26 that is associated with the Location
Information Management System 58. Each record 75 may include one or
more of the following types of information, each of which defines
its own separate database field: 1) a cell or cell sector field 77
which identifies a particular cell 22 or cell sector 26; and 2) one
or more PDE site fields 70, which generally correspond to the PDE
site field in the PDE site database and which identify (e.g., via a
server address) those PDE sites 50 that are available for providing
some sort of location information on a particular Mobile
Communications Unit 14 when within the cell 22 or cell sector 26
associated with the particular record 75. Any data storage
technique may be utilized, e.g., although the discussion above
denotes separate databases, the associated information may be
included in or conceptualized as tables of a single relational
database. What is of importance is that each cell 22 or cell sector
26 encompassed by the Location Information Management System 58 in
the illustrated system be associated with a "list" of PDE sites 50
that would be able to provide location information on a particular
Mobile Communications Unit 14 when in this cell 22 or cell sector
26. That is, once the Location Information Management System 58
determines or otherwise receives information on which cell 22 or
which cell sector 26 a particular Mobile Communications Unit 14 is
currently located in, the Location Information Management System 58
may consult the cell/PDE site database 72 to determine if there are
any PDE sites 50 stored in relation to this cell 22 or cell sector
26 so as to be able to provide location information on the
particular Mobile Communications Unit 14.
[0043] Another source of information that may be utilized by
Location Information Management System 58 is a collection of
information on each of the various Mobile Communications Units 14
of the mobile communications network 10. One such source is
illustrated in FIG. 6 and is in the form of a home location
register database 100. As in the case of the PDE site database 62
and the cell/PDE site database 72, the home location register
database 100 will typically reside on an appropriate
computer-readable storage medium.
[0044] The home location register database 100 of FIG. 6 may be
generally viewed as containing a database record 104 on each Mobile
Communications Unit 14 of the mobile communications system 10. Each
record 104 may include one or more of the following types of
information, each of which defines its own separate database field:
1) a mobile unit field 108 for storing information which somehow
identifies and which is unique to a particular Mobile
Communications Unit 14 (e.g., an Electronic Serial Number
(ESN)/Mobile Identification Number (MIN), or a telephone number,
for the subject Mobile Communications Unit 14); 2) a subscriber
name field 112 for storing information which identifies the party
that has subscribed to the services provided by the mobile
communications system 10 in association with the subject Mobile
Communications Unit 14; 3) a subscriber address field 116 for
storing information which identifies the address of the party that
has subscribed to the services provided by the mobile
communications system 10 in association with the subject Mobile
Communications Unit 14; 4) a position determination capabilities
field 120 for storing information which defines the position
determination capabilities of the subject Mobile Communications
Unit 14 (e.g., whether the same includes a GPS transceiver or other
handset-based location finding capabilities); 5) a physical
location field 124 for storing information which identifies the
last known physical location of the subject Mobile Communications
Unit 14; and 6) a physical location time field 128 for storing
information which identifies the time associated with the
information contained in the physical location information field
124 (e.g., the physical location information in the field 124 was
obtained at a specified time on a specified day in a specified
year). It will be appreciated that any way of storing the type of
information set forth in the home location register database 100
may be utilized by the Location Information Management System 58.
Moreover, other types of information could be stored in relation to
each Mobile Communications Unit 14 as well, including further
information, which relates to the location information contained in
the physical location field 124 (e.g., the accuracy or uncertainty
of the specified physical information), and may then be made
available to the Location Information Management System 58. The
Location Information Management System 58 may consult the home
location register database 100 upon receiving a request for
location information on a particular Mobile Communications Unit 14
to determine if the particular Mobile Communications Unit 14 itself
has location finding capabilities and/or to determine if the last
known physical location of the particular Mobile Communications
Unit 14 satisfies the outstanding request for location
information.
[0045] FIG. 7 presents an embodiment of a system/PDE capabilities
database 200 which may be utilized by the Location Information
Management System 58, when a general location of the Mobile
Communications Unit is not provided with the location request or
otherwise available. The illustrated system/PDE database 200
contains a database record 204 for each type of PDE technology
utilized in the PDE system 46 associated with the Location
Information Management System 58. Each record 204 may include one
or more of the following types of information, each of which
defines its own separate database field: 1) PDE type 206; 2) a
system average determination accuracy 208; 3) a system average
response time 210; 4) a system average computation cost 212. Each
of the entries provides an average value for the particular type of
PDE utilized by the PDE system 46. In this regard, if a location
information request is received at the Location Information
Management System 58 without a general location such that an
individual PDE site may not be selected based on that general
location, the Location Information Management System 58 may select
the type of PDE site 50 in the PDE system 46 that may be utilized
to provide the requested information. In this case, the Location
Information Management System 58 will produce a request for
location information to a platform of the PDE system 46 to locate a
particular mobile communication unit 14 using the specified type of
position determining equipment. The PDE system 46 then has the
responsibility to invoke the designated PDE site 50 covering the
area where the Mobile Communications Unit is currently located. As
will be appreciated, the PDE system 46 is generally in
communication with various components of the mobile network 10 and
may therefore be able to determine the mobile communication unit's
general location through various known means (e.g., an HLR query,
cell identification information messages used for call routing,
etc.)
[0046] Another function provided by the Location Information
Management System 58 is to manage requests for location information
for Mobile Communications Units 54 of the mobile communications
system 10. Although these requests will typically be transmitted by
a location based application 54 which generally interfaces with the
Location Information Management System 58 through interface 60, the
illustrated system 58 contemplates providing location information
for Mobile Communications Units 14 to any authorized party which
requests location information for a given Mobile Communications
Unit 14, directly or indirectly, from the Location Information
Management System 58. FIG. 8 presents one embodiment of location
information management protocol 700 which may be utilized by the
Location Information Management System 58 of FIGS. 1 and 3 for
selecting a PDE site 46 to provide location information for a
particular Mobile Communications Unit 14 when a general location is
provided. The Location Information Management System 58 may include
at least one processor 150 in this regard for executing the
functionality of the protocol 700. However, any way of
appropriately executing the protocol 700 in the context of the
mobile communication system 10 may be utilized.
[0047] The illustrated protocol 700 of FIG. 8 is initiated by
receiving (710) a request at the Location Information Management
System for location information for a particular Mobile
Communications Unit. This request for location information may
originate from one of the location based applications 54 or from
any source that properly interfaces with the Location Information
Management System 58. This request may include one or more
requirements or specifications that are associated with the desired
location information to be provided by the Location Information
Management System 58. In accordance with the present invention,
some of these specifications may be in the form of a predefined
user selectable ranges of QoS parameters e.g., low, medium, high
accuracy. For exemplary purposes, the illustrated protocol
implementation assumes that two QoS parameters have been received
with the location request, such as a geographical accuracy
parameter and time of response requirement.
[0048] The location information management protocol 700 of FIG. 8
continues searching (720) a location cache 160 associated with the
Location Information Management System 558 to determine if the
cache 160 includes location information satisfying the requirements
of the request. The illustrated location cache 160 contains a
record on each Mobile Communications Unit 14 within the mobile
communication system 10. This record includes information on the
last known physical location of the corresponding Mobile
Communications Unit as well as a time associated with this last
known physical location. This information may be acquired from, for
example, a previous location request or through a home location
register associated with the Mobile Communications Unit 14. The
Location Information Management System 58 searches the location
cache 160 to identify the relevant record 165 using for example the
Mobile Communications Unit's mobile identification number (MIN). If
the information in the record 165 meets all the requirements
specified in the request, the information is retrieved from the
location cache and directed (730) to the recipient designated by/in
the request. In the event that satisfactory location information
for a particular Mobile Communications Unit 14 is not currently
stored in the location cache 160, the general location of the
Mobile Communications Unit, if available, is accessed from the
request or otherwise obtained and, if necessary, processed to be in
a standard format for use with the Location Information Management
System 58.
[0049] Once a general location of the Mobile Communications Unit 14
is known, the processor 150 associated with the Location
Information Management System 58 uses the general location
information such as a cell sector to search (750) the Cell/PDE
database 72 to determine if any local PDE sites 50 are capable of
providing location information for the Mobile Communications Unit
14 identified in the request. Generally, the database 72 is
searched to produce a `list` of identifiers associated with the PDE
sites 50 capable of providing location information for an area that
includes at least part of and, more preferably, encompasses the
entirety of, the general location of the Mobile Communications Unit
14. Once these PDE identifiers are obtained, they may be used to
search records 66 in the PDE site database 62 to identify one or
more a PDE sites that can provide the location information.
[0050] The illustrated protocol then proceeds by determining if the
Mobile Communications Unit 14 is associated with a handset-based
position determining equipment site 46. In this instance, the
processor 150 associated with Location Information Management
System 58 will search (760) a Mobile Communications Unit database
100 which may be a HLR database for a particular Mobile
Communications Unit 14 to determine what capabilities are available
for the desired Mobile Communications Unit 14. In this regard, if a
particular Mobile Communications Unit 14 supports, for example,
TDOA position determination but not GPS, the available PDE 50 is
correlated with this data and those PDEs which are handset-based,
as noted by field 96, that are not supported by the Mobile
Communications Unit 14 will be eliminated from consideration.
[0051] At this point, all PDE sites 50 capable of providing
location information for the Mobile Communications Unit 14 are
identified by combining (770) information from the PDE site
database and the HLR database in a `list.` Next, the one or more
QoS parameters from the location information request may be
compared (780-790) to the list of capable PDE sites to select a
site for providing the desired information according to the
specified parameters. For example, in the case where the first QoS
parameter specifies a "medium" geographical accuracy, the processor
150 will begin to search the records associated with each listed
PDE site 50 to determine if they provide at least medium
geographical location information. As will be appreciated, at some
point prior to initiation of the protocol 700, the ranges
associated with each specification (geographical accuracy, cost,
timeliness, etc.) will have been defined. For example, a location
request may be provided via interface 60 from a location based
application 54 requesting medium geographical accuracy. The
Location Information Management System 50 may then convert this
specification into a standard format that may be used in accordance
with the present invention. For example, in the case of
geographical accuracy, the Location Information Management System
58 may be configured such that low accuracy corresponds with an
uncertainty of 750 meters or more, medium accuracy is location
information with an accuracy between 300 and 750 meters and high
geographical accuracy is defined as location information within a
300 meter radius. Accordingly, the protocol compares (780) the
first parameter (e.g., medium geographical accuracy) with the
corresponding attribute, which is expressed in standard terms, for
each PDE site 50. In particular, the database records for each of
the identified PDE sites 50 on the list is compared with the
parameter. In the case of a parameter requesting medium
geographical accuracy, all PDEs which provide high or low
geographical accuracy are eliminated from consideration for
selection (high accuracy PDEs may also be eliminated depending on
the specific implementation of the protocol, e.g., the protocol may
allow for specification of "at least medium" or "only medium." As
will be appreciated, the interface 60 and Location Information
Management System 58 may be configured such that any QoS parameter
may be assigned a standardized value with and compared to any value
in PDE database record 66. For example, low, medium and high
geographical accuracies may be correlated with PDE types (i.e.,
low=cell sector, medium=TDOA, and high=AGPS) and then correlated
with the position determination technology type 74 of the database
record 66. As will be appreciated, this arrangement provides great
flexibility in comparing QoS attributes with PDE capabilities and
allows for changes in system capabilities to be implemented without
necessarily changing the QoS parameters used by the location based
applications.
[0052] If the location request contains a second specification the
protocol proceeds to perform an appropriate comparison (790), again
limiting the number of PDE sites 50 available to provide the
desired location information. Once all such limiting steps of the
protocol are completed, a PDE site 50 is selected and invoked (800)
to provide the desired location information. It may, of course,
turn out that multiple PDE sites 50 will be appropriate for
determining the physical location of the Mobile Communications Unit
14. In this case, the Location Information Management System 58 may
be configured such that it invokes all identified PDE sites 50 or
invokes some sort of default selection criteria to select among the
remaining PDE 46 sites. For example, the attributes listed in each
PDE's record 56 in the PDE site database 62 may be utilized to
select among the remaining PDE sites 50. Thus, in the case where
three PDEs are identified as meeting the specifications from the
location request, it may be possible to select among the three
using a nonspecified attribute such as cost or any other attribute
not already specified in the request. Alternatively, a client
profile database may be consulted to determine default
characteristics for individual clients. Thus, a client application
may specify the use of a given PDE (e.g., due to a favorable
relationship with that provider) whenever possible.
[0053] It, of course, may also turn out that none of the PDE sites
50 or other PDE sources will be appropriate for determining the
physical location of Mobile Communications Unit 14. In this case,
an error message may be sent (810) by the Location Information
Management System 58 that provides an indication to the requesting
entity that no location information is available for the Mobile
Communications Unit 14 in accordance with the specified
parameters.
[0054] Once a PDE site 50 is selected, the Location Information
Management System 58 can transmit an invoke message to the PDE site
50 or the PDE system 46 to have the selected PDE site or system
obtain and return to the Location Information Management System 58
location information for the specified Mobile Communications Unit
14. Once the Location Information Management System 58 receives the
location information, it is translated to a standard form as
defined by the interface and transmitted (820) to the requesting
entity or other specified location.
[0055] The foregoing description of the present invention has been
presented for purposes of illustration and description.
Furthermore, the description is not intended to limit the invention
to the form disclosed herein. Consequently, variations and
modifications commensurate with the above teachings, and skill and
knowledge of the relevant art, are within the scope of the present
invention as defined by the following claims.
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