Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Method for routing calls based on subscriber's location
The invention relates to a method according to the preamble of claim 1 for
updating
subscriber location. The invention also concerns methods according to the
preambles
of claims 5 and 14 for routing a call on the basis of subscriber location.
These kinds of methods are employed in such telecom services or similar
functions
in which the location of the A-subscriber and the B-subscriber are important
factors
in the execution of the service or other similar function. The location data
of the A-
subscriber can be utilized when, e.g., calls placed on the nation-wide number
of a
firm are to be routed to local offices of the firm that are located closest to
the calling
party. Respectively, the location data of the B-subscriber can be utilized
when, e.g.,
announcements or advertisements are desired to be transmitted over
I 5 telecommunication channels to connections located within a given
geographical area.
In the prior art, the location of a subscriber has been resolved in wireline
telephone
networks on the basis of the A-subscriber identity and the address data linked
thereto
in a corresponding data base. In this fashion, it has been possible in a
wireline
telecommunications network to define a certain geographical area separately
from
other areas by compiling the subscriber number plans of said area into a look-
up
table. The look-up table compilation method of A-subscriber numbers can be
employed to create most comprehensive and useful control arrangements with the
provision that the A-subscriber number spaces of the different geographical
areas are
definable in a unique fashion. This must be understood so that all the numbers
of
subscriber connections within a given area begin with the same sequence of
digits. In
Finland, it has also been possible to utilize the data base of a nation-wide
directory
assistance service. In mobile telephone networks, however, the location the
calling
party cannot be resolved on the basis of the A-subscriber identity, because
mobile
telephone users can typically move over large areas both domestically and
abroad.
The situation is further complicated by the fact that mobile telephones are
frequently
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used abroad by roaming in the networks of nonlocal operators.
Conventionally, it has been possible to resolve the location of a mobile
telephone
unit used in the network of a local operator from the location information, or
cell
identification data, submitted by the operator's mobile telephone network.
Hereupon,
the operator has known the mobile telephone unit location by the area of the
network
cell currently serving the subscriber. If subscriber location has been desired
to be
resolved with a greater precision that at the cell level alone, it has been
possible to
redefine the location of the mobile telephone by combining the information
obtained
from three neighboring mobile telephone network cells closest to that serving
the
subscriber. Analogously to the wireline telephone network techniques, it has
also
been possible to compile table associated with given geographical areas.
Herein, the
geographical areas have been determined from the cell identification data of
the
mobile telephone network.
The prior-art techniques have been hampered by the need to maintain separate
systems for resolving the location of wireline connections and mobile
telephones.
A further problem of the conventional resolution method of subscriber location
in
wireline networks is that the method is based on the assumption that the
number
identities of A-subscribers within a given geographical area can be compiled
into a
look-up table in the above-described fashion. However, the fact today is that
the
numbers identifying the A-subscribers within a certain area are typically
scattered
over number series beginning with different digit sequences, where it is no
more
possible to manage the number spaces of A-subscribers by the decadic number
series, but instead an exhaustive list of allocated A-subscriber numbers is
needed.
The compilation and updating of such a look-up list is extremely awkward and
prone
to error. Moreover, this type of system requires continuous and fast data
transfer
between the administrative and call routing data bases of different telecom
operators
in the case that the service is intended to be available also across the
operating
boundaries of different telecom operators. Furthermore, the conventional
technique
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of compiling subscriber numbers into look-up tables on the basis of locally
allocated
number series is not feasible in the future, because number portability to be
imple-
mented over all telecom networks will undermine this kind of number look-up
table
approach. Obviously, as all subscribers in the near future will have the
possibility of
porting the telephone number of their subscriber connection when moving from
one
place to another, the telephone number look-up lists of A-subscriber
identities in
different geographical areas are subject to change frequently.
Respectively, the method conventionally used in a mobile telephone network for
resolving the location of a mobile telephone unit is problematic. Also in
mobile
telephone networks, subscriber location data or cell identification codes in
database
tables must be updated on a continuous basis, because the cell area dimensions
of
radio networks require frequent readjustments with the development of the
network,
whereby new cell identification codes must be allocated and obsolete ones
deleted.
Furthermore, it is possible that cell overlap must be altered dynamically with
the
daily traffic peaks. Moreover, resolving a subscriber location on the basis of
cell
identification codes is not possible over the network limits of different
telecom
operators, because the geographical locations of cells and the respective cell
identification codes of one mobile telephone operator are not accessible to
other
telecom operators.
It is an object of the present invention to overcome the above-described
drawbacks
and to provide entirely novel types of methods for updating the location data
of a
subscriber connection in a telephone network, for determining the location
area of
the connection, as well as for routing calls on the basis of the subscriber
location
data.
The goal of the invention is attained by virtue of using coordinates for
defining the
location of a subscriber connection. The coordinate system employed herein is
ad-
vantageously a conventional coordinate system, in which the location of any
connec
tion can be resolved with the help of, e.g., a satellite positioning system by
the
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subscriber or network terminal device using the connection. According to the
invention, the coordinates of the connection are transmitted from the
connection over
the telecom network to a location data base maintained by at least one telecom
operator. When calls are routed according to the invention, the location of
the A-
subscriber and/or the B-subscriber, or even of both parties as required are
analyzed
by retrieving the coordinates of the respective connection from said location
data
base. If so needed, the coordinates can be interpreted with the help of
linking data
stored in another data base, called a linking data base, where the coordinates
of the
connection corresponding to given geographical areas are linked with each
other. In
a service resolving the A-subscriber location, the incoming call can be
routed, e.g., to
the telephone exchange of the firm owning the destination extension and the
location
coordinates of the A-subscriber or the geographic location area of the calling
party
that are/is resolved from the coordinates can be transmitted over a
communication
channel to the called firm in order to aid the firm's internal call
forwarding. The
location of the calling party and the call routing routine linked thereto may
also be
exhaustively analyzed and defined in the system of the telecom operator with
the
provision that authorization to such an operation has been given.
More specifically, the methods according to the invention are characterized by
what
is stated in the characterizing parts of claims l, 5 and 14.
The invention offers significant benefits.
The invention facilitates both wireline and mobile telephone networks to
perform an
accurate and reliable call routing based on resolving the locations of the A-
and/or
the B-subscriber.
The embodiments of the invention which utilize satellite positioning systems
have
the additional advantage that, when so desired, the method is applicable in
any geo-
graphical location inasmuch satellite positioning systems are today globally
deployed. The association of subscribers from wireline and mobile telephone
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networks into users of the service is not dependent on the telecom operator or
the
country of the subscribers with the assumption that their local telecom
operator can
transfer the A-subscriber number of the calling party and the coordinate
information
to the location data base of the telecom operator actually providing the
routing
service. This feature is particularly useful for travelers located abroad and
having
their mobile telephone with them. The location of mobile telephone units may
also
be of great use in internationally operating firms inasmuch the invention
gives the
firms a method for globally locating their employees traveling abroad. Thus,
the firm
can easily check, e.g., whether any of their people is located in a given
country.
When the invention is applied so that the operator providing the caller-
location-
based call control service can utilize the directory assistance service data
base of the
operator serving the subscriber, the location information of the subscriber
using the
caller-location-based call control service can be linked to a plurality of
different geo-
graphical values. Thus, it is possible to determine, e.g., the county, city or
community in which the calling party resides. When so desired, the subscriber
location may also be refined down to the zip code, city area or, in the most
accurate
systems, the street address. Then it is easy to offer the calling party, e.g.,
a service
capable of telling his exact location in a proper format within the resolution
limits of
the satellite positioning system.
If the invention is applied in an alternative manner so that the subscriber
location
data is linked with the information systems of the service-providing
operators, the
service providers can by themselves in a flexible manner design and maintain
call
routing lists suited to serve their own applications. Then, a call placed to
the service
number of a gas station operator can be directed to, e.g., the operator's gas
station
which is open closest to the caller or, similarly, a call placed to a pizzeria
chain
number can be directed to a pizzeria closest to the caller. This advantageous
embodiment allows the invention to be used for routing calls placed to the
numbers
of a great variety of different firms, organizations and authority bodies.
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The invention may also be applied so that a location data base is first
searched for
subscriber numbers fulfilling certain criteria as to their location. The
subscriber
number list thus obtained can be used as such or compared with information
retrieved from some other data bases in order to limit the amount of numbers
in the
S subscriber list. Next, announcements or advertisements can be transmitted to
the sub-
scriber numbers of the thus selected group, whereby the announcements or
advertise-
ments are focused to subscribers having a connection within a desired
geographical
area. By this type of embodiment, the invention makes it possible to select,
e.g.,
mobile telephone units located within a given area of the city and to send
within said
area a text message to all the mobile telephone connections that support the
function
of the subscriber location resolution service. Transmission to selected
wireline
connections can be accomplished with the help of a human operator or, e.g.,
robotic
calling machine.
In regard to subscriber number portability in wireline telephone networks, an
advan-
tageous embodiment of the invention makes it possible for the subscriber to
per-
sonally update in simple manner the link between the coordinates of his new
living
or stay location and the number corresponding to his A-subscriber identity,
whereby
call routing to the new location of the ported number will be effective
without delay.
The development in microelectronics and mobile telephone technology over
recent
years has also facilitated the integration of device receiving satellite
positioning data
with a mobile telephone into a single unit. US Pat. No. 5,786,789 also
discloses a
modular combination unit having the mobile telephone unit and the GPS unit
implemented detachable from each other. The mobile telephone unit described in
cited publication can be used for sending position-locating data from the
mobile
telephone to the public telephone network. One advantageous embodiment of the
present invention uses a mobile telephone equipped with a satellite
positioning
system device such as a GPS receiver. In this advantageous embodiment, the
combination mobile telephone-satellite positioning system receiver is
programmed to
send its positioning data automatically to the subscriber location data base.
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In the following, the invention is described in more detail with reference to
exempli-
fying embodiments illustrated in appended drawings in which
Fig. 1 illustrates a method according to the invention, wherein the location
data base
is updated from a wireIine network connection;
Fig. 2 illustrates a method accordirig to the invention, wherein a call is
routed on the
basis of subscriber location resolved from a wireline telephone network
connection;
la
Fig. 3 illustrates a method according to the invention, wherein the location
data base
is updated at the instant a subscriber activates the location-based call
control service
from a mobile telephone network;
Fig. 4 illustrates a method according to the invention, wherein the location
data base
is updated at the instant the location of a subscriber calling from a mobile
telephone
network changes; and
Fig. 5 illustrates a method according to the invention, wherein a call is
routed on the
basis of subscriber location resolved from a mobile telephone network.
In the description of the invention and in the claims, the term A-subscriber
is used
for making reference to the telephone connection from which the call is
initially
placed. Respectively, the term A-subscriber identity is used for making
reference to
the identifying code of the caller's telephone connection in a public
telephone
network. The identifying code may be numeric, for instance. The numeric A-
subscriber identity code is also referred to as the A-subscriber number.
Respectively, in the description of the invention and in the claims, the term
B-
subscriber is used for making reference to the telephone connection to which
the call
is routed after possible call control operations. Hence, while starting a call
and
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dialing a telephone number at the A-subscriber end, it is not yet necessarily
known to
which particular B-subscriber the call is to be connected. Thus, the call may
address
a group of potential B-subscribers, among which the B-subscriber (or possibly
even a
plurality of B-subscribers) will be selected. Accordingly, the B-subscriber
connection in the context of the present invention must be understood to
represent
some type of destination connection for the call.
Referring to Fig. I, the system shown therein comprises an SSP (Service
Switching
Point) 1 in an intelligent telephone network, an SCP (Service Control Point)
data
base 2 controlling the operation of the SSP l, and a location data base 3
connected
over a communication channel to said SCP data base 2. Furthermore, the system
shown in Fig. 1 includes a local exchange 6 of the telephone network and a
wireline
connection 5 interfaced to the same.
The method illustrated in Fig. 1 can be used when, e.g., a subscriber
connected to a
wireline telephone network decides to become a user of the location-based call
control service or moves his connection to another location. Using the method
of
Fig. 1, the following steps are perfornled when the location data base is
updated over
a wireline telephone connection:
1 I ) The subscriber of a wireline network calls from his connection 5 to a
location-based call control service activation number, whereby his terminal
establishes a connection to his local exchange 6.
12) The call is directed from the local exchange 6 to the closest SSP
switching
center 1, and thereupon the SSP switching center 1 triggers the location-
based call control service to serve the service activation number.
13) The SSP switching center 1 performs a query to the SCP data base 2 for
further steps in the redirection of the call. The SCP data base 2 requests the
SSP switching center 1 to issue a suitable message for performing the service
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activation. The SSP switching center 1 registers, according to the
instructions
issued by the SCP data base 2, digits dialed in the dual-tone multiple-
frequency format by the subscriber. The subscriber selects to activate the
location-based call control service for his subscriber number 5. The
S subscriber dials his local coordinates according to instructions issued to
him.
14) The SCP data base 2 updates the callers' A-subscriber identity 5 and local
coordinates in the location data base 3.
The subscriber of a wireline telephone network can obtain the coordinates of
his
location using a satellite positioning system receiver, for instance. E.g., if
a GPS
satellite positioning system is utilized, the location-based call control
system can be
adapted to function according to the coordinate convention employed in the GPS
satellite positioning system, whereby the subscriber can submit the parameter
values
of his location directly in same format as given by the GPS receiver. However,
there
is no particular reason for the use of the GPS positioning system in
conjunction with
the present invention, but it is equally possible to apply the invention in
conjunction
with other satellite positioning systems such as the GLONASS. When the
subscriber
decides to log into the location-based call control service, the location
coordinates of
the subscriber's wireline connection 5 can be sent to the telecom operator of
the
service either directly or by placing a call to a specific service number.
The system shown in Fig. 2 comprises the system of Fig. 1 complemented with a
linking data base 4 that is connected over a communication channel to the SCP
data
base 2. The linking data base 4 can be, e.g., a data base used by a directory
service
having, e.g., subscriber numbers and the corresponding subscriber identities
and
addresses stored therein. Obviously, the linking data base 4 may also contain
other
information or be based on an entirely different information content. For
instance,
the linking data base 4 may contain information on the country, county,
community,
city or street address to be linked with a set of given coordinates.
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The linking data base 4 can be utilized, e.g., so that the location data
retrieved from
the location data base 3 triggers a query to the linking data base 4, and the
response
is a geographical area or other information corresponding to the location
information
given in the coordinate format. Later in this application, such geographical
5 information corresponding the coordinates will be referred to as location
area
information. The information thus retrieved can be further utilized for
routing the
call ahead. The retrieved information may also be transmitted, when so
desired, from
the SCP data base to, e.g., the terrriinal device of the call destination
connection, the
service provider's information system or an automatic voice response unit.
Using the method of Fig. 2, the following steps are performed when the
location data
of a wireline telephone network subscriber is used for routing a call:
21 ) The subscriber dials a number having its call control linked with the
location-
based call control service.
22) The call is directed to the closest SSP switching center 1, and thereupon
the
SSP switching center 1 triggers the service for the dialed number.
23) The SSP switching center 1 performs a call control query to the SCP data
base 2.
24) In the analysis of the dialed number, the SCP data base 2 detects that
calls
placed to the dialed number also require an analysis of the calling party's
location, whereby a query is made to the location data base 3.
25) After receiving the coordinates of the calling party's location from the
location data base 3, the SCP data base 2 retrieves the location area
information from the linking data base 4 in a relevant format corresponding
to the caller location coordinates. The SCP data base 2 uses the caller
location area information related to the caller location for defining a
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destination number determined by the control logic for the called number, a
charging rate or other parameter. The SCP data base 2 transmits the SSP
switching center 1 instructions for redirecting the call.
26) The SSP switching center 1 connects the call to the defined destination
number.
27) The SCP data base 2 may, if so required, transmit information on the
caller
location coordinates or corresponding data retrieved from the linking data
base 4 to the local telephone exchange or system, private branch exchange or
voice response unit, answering at the destination number. This information is
transmitted separately over the communications network.
The system illustrated in Fig. 3 is similar to those shown in Figs. 1 and 2 by
compris-
IS ing an SSP switching center I, an SCP data base 2 and a location data base
3. In
addition to these, the system of Fig. 3 includes a mobile telephone switching
center 8
communicating with the SSP switching center I, a short-message center 9
communi
cating with the mobile telephone switching center 8 and the location data base
3, and
a mobile telephone connection 7 located within the coverage area of the mobile
tele
phone switching center 8.
Advantageously, the mobile telephone connection 7 is used from a mobile
telephone
incorporating a satellite positioning device. The combination mobile telephone-
satellite positioning device is programmed according to the advantageous
embodi-
ment so as to transmit changes in its position coordinates automatically.
Herein, the
mobile telephone sends its position data automatically to the location data
base 3
whenever the coordinates of the mobile telephone location differ by a value
defined
in a predetermined rule from those of previously updated location data. In
this
fashion, the accuracy of updated data can be programmed desiredly within the
confines of the resolution of the satellite positioning system used.
Accordingly, the
system disclosed herein makes it possible to implement a very accurate and
almost
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real-time updated monitoring of subscriber location. Alternatively, the
location
updating can be made at given intervals or the rule of coordinate updating can
be
formulated as a function of time and distance of position change.
The mobile telephone unit can update its location data using, e.g., short
messages.
The short messages are sent to the location data base 3 which may also be such
a
data base that is jointly used by several telecom operators. The location-
based call
control service can be activated by; e.g., placing an activation call by the
mobile
telephone network subscriber to a special service number, and by sending the
subscriber location coordinates in a short message. After this first
activation call, the
subscriber's mobile telephone unit keeps sending the location data in the
above-
described manner until the service is inactivated.
Using the method of Fig. 3, the following steps are performed when the
location data
base is updated over a mobile telephone connection:
31 ) The subscriber using the mobile telephone unit calls from his connection
7 to
a location-based call control service activation number.
32) The call is directed via the mobile telephone switching center 8 to the
closest
SSP switching center 1, and thereupon the SSP switching center 1 triggers the
location-based call control service to serve the service activation number.
33) The SSP switching center 1 performs a query to the SCP data base 2 for
further steps in the redirection of the call. The SCP data base 2 requests the
SSP switching center 1 to issue a suitable message for performing the service
activation. The SSP switching center 1 registers the dual-tone multiple-
frequency digits dialed by the subscriber according to the instructions issued
to him by the SCP data base 2. The subscriber selects to activate the location-
based call control service for his subscriber number 7.
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34) The SCP data base 2 requests the location data base 3 to activate the
service
for the subscriber's mobile telephone number 7.
35) The location data base 3 relays the activation request as a short message
to
the short-message center 9.
36} The short-message center 9 relays the short message to the mobile
telephone
switching center 8.
37) The mobile telephone switching center 8 sends the short message further to
the mobile telephone unit used by the subscriber connection 7, thus activating
the unit's system for satellite positioning information reception.
38) The mobile telephone unit used by the subscriber connection 7 sends the
real-
time coordinate values of its location as a short message to the mobile
telephone switching center 8.
39) The mobile telephone switching center 8 sends the short message further to
short-message center 9.
40) The short-message center 9 relays the short message to the location data
base
3, where the coordinate information of the short message is interpreted and
the correspondence link between the A-subscriber identity and its coordinates
is updated.
41 ) The location data base 3 sends the SCP data base 2 an acknowledge message
confirming successful activation of the location-based call control service.
The SCP data base 2 requests the SSP switching center 1 to send an
appropriate announcement to the caller confirming the operation.
The system illustrated in Fig. 4 is similar to that shown in Fig. 3 by
comprising a
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location data base 3, a mobile telephone subscriber connection 7, a mobile
telephone
switching center 8 and a short-message center 9.
Using the method of Fig. 4, the following steps are performed when the
location data
base is updated over a mobile telephone connection:
45) If the location-based call control service currently serving the mobile
tele-
phone connection 7 is already in active state, the movement of the mobile
telephone connection 7 over a sufficiently long distance away from area
defined for the connection by the location data base 3 on the basis of the
coordinate values previously sent to the data base causes the mobile
telephone unit to send a new short message with updated location data to the
location data base 3.
1 S 46) The mobile telephone switching center 8 relays the short message to
the
short-message center 9.
47) The short-message center 9 relays the short message to the location data
base
3 where the message is interpreted and the required updating of data is
performed.
The system illustrated in Fig. 5 is similar to that shown in Fig. 3 and
complemented
in the same manner as in Fig. 2 with a linking data base 4 connected over a
commu-
nication channel to the SCP data base 2.
Using the method of Fig. 5, the following steps are performed when call
control is
implemented on the basis of subscriber location in a mobile telephone network:
S 1 ) The subscriber using a mobile telephone connection 7 dials a number
having
its call routing linked with the location-based call control service.
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52) The call is directed to the closest SSP switching center 1, and thereupon
the
SSP switching center 1 triggers the service for the dialed number.
53) The SSP switching center 1 performs a call control query to the SCP data
5 base 2.
54} In the analysis of the dialed number, the SCP data base 2 detects that
calls
placed to the dialed number also require an analysis of the calling party's
location, whereby a query is made to the location data base 3.
55) After receiving the coordinates of the calling party's location from the
location data base 3, the SCP data base 2 retrieves the location area
information from the linking data base 4 in a relevant format corresponding
to the caller location coordinates. The SCP data base 2 uses the caller
location area information for defining a destination number determined by
the control logic for the called number, a charging rate or other parameter.
The SCP data base 2 transmits the SSP switching center 1 instructions for
redirecting the call.
56) The SSP switching center 1 redirects the call to the destination
connection
defined by the SCP data base 2.
57) The SCP data base 2 may if so required transmit information on the caller
location coordinates or similar data retrieved from the linking data base 4 to
the local telephone exchange or system, private branch exchange or voice
response unit, answering at the destination number. This information is
transmitted separately over the communications network.
Without departing from the scope and spirit of the invention, embodiments
different
from those described above may also be contemplated. While the afore-discussed
call control method is based on the location of either the A-subscriber or the
B-
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subscriber, the invention may as well be utilized so that the call control
occurs based
on the locations of both parties. Such a call control based on both the A-
subscriber's
and the B-subscriber's location is practicable, e.g., for help service
numbers,
whereby a call received from, e.g., the driver of defective car on the road
can be
connected directly to a towing service firm's mobile telephone unit located
closest to
the car needing help. The same concept may also be applied to the control of
distress
calls. A call control service based on the analysis of A-subscriber and/or B-
subscriber locations is also useful, e.g., for ordering a taxi service,
whereby the
subscriber using a mobile telephone can call for a taxi without knowing the
address
of his present location.
The above-described advantageous embodiments of the invention were illustrated
using the conventional geographic coordinate system based on latitudes and
longi-
tudes for defining the position coordinates. However, the invention is equally
well
applicable in any other coordinate system. Hence, the term location coordinate
data
in the context of the present invention must be understood in a general sense
referring to any such representation of position data that allows the location
of a
connection to be defined in a unique manner in a predetermined coordinate
system
with the help of, e.g., the values of two parameters.
