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Claims  |
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What is claimed is:
1. A method of informing a home cellular telephone service region of a
cellular telephone network of a location of a customer having a cellular
telephone unit located proximate to a mobile data terminal in a foreign
cellular telephone service region of the cellular telephone network
comprising the steps of:
automatically providing a first signal identifying the customer from the
mobile data terminal to a mobile data base radio station of a mobile data
network;
determining the foreign cellular telephone service region in which the
customer is located based upon a location of the mobile data base radio
station; and
transmitting data identifying the customer and the foreign cellular
telephone service region in which the customer is located from the mobile
data base radio station to the home cellular telephone service region of
the customer.
2. The method according to claim 1, wherein the determining step includes
the step of determining the identity of a foreign cellular telephone
service provider to which the customer has access.
3. The method according to claim 1, further comprising the step of
automatically providing a second signal identifying the home cellular
telephone service region from the mobile data terminal to the mobile data
base radio station.
4. The method according to claim 3, wherein the first and second signals
are provided from the mobile data terminal immediately after the mobile
data terminal is turned on.
5. The method according to claim 1, wherein the data identifying the
customer and the foreign cellular telephone service region is transmitted
from a clearing house to the home cellular telephone service region.
6. The method according to claim 1, wherein the foreign cellular telephone
service region is determined through the use of a look-up table.
7. The method according to claim 1, wherein the cellular telephone unit and
the mobile data terminal are contained within an automobile.
8. The method according to claim 1, wherein the cellular telephone unit and
the mobile data terminal are integrated in a hand-carried, portable unit.
9. The method according to claim 1, further comprising the step of routing
a telephone call for the customer from the home cellular telephone service
region to the foreign cellular telephone service region.
10. The method according to claim 1, further comprising the step of
transmitting a telephone number of a party calling the customer from the
home cellular telephone service region to the foreign cellular telephone
service region.
11. A method of informing a home cellular telephone service region of a
cellular telephone network of a location of a customer having a cellular
telephone unit electrically coupled to a mobile data terminal in a foreign
cellular telephone service region of the cellular telephone network,
comprising the steps of:
transmitting a first data signal identifying the foreign cellular telephone
service region in which the customer is located from the foreign cellular
telephone service region to the cellular telephone unit;
transmitting the first data signal from the cellular telephone unit to the
mobile data terminal;
transmitting the first data signal, a second data signal identifying the
home cellular telephone service region of the customer, and a third data
signal identifying the customer from the mobile data terminal to a mobile
data base radio station of a mobile data network; and
transmitting the first and third data signal from the mobile data base
radio station to the home cellular telephone service region of the
customer.
12. The method according to claim 11, wherein the transmission from the
cellular telephone unit to the mobile data terminal includes the step of
transmitting the identity of a foreign cellular telephone service provider
to which the customer has access.
13. The method according to claim 11, wherein the first, second and third
data signals are automatically transmitted immediately after the mobile
data terminal is turned on.
14. The method according to claim 11, further comprising the steps of:
transmitting the first, second and third data signals from the base radio
station to a clearing house; and
transmitting the first and third data signals from the clearing house to
the home cellular telephone service region.
15. The method according to claim 11, wherein the cellular telephone unit
and the mobile data terminal are contained within an automobile.
16. The method according to claim 11, wherein the cellular telephone unit
and the mobile data terminal are integrated in a hand-carried, portable
unit.
17. The method according to claim 11, further comprising the step of
routing a telephone call for the customer from the home cellular telephone
service region to the foreign cellular telephone service region.
18. The method according to claim 11, further comprising the step of
transmitting a telephone number of a party calling the customer from the
home cellular telephone service region to the foreign cellular telephone
service region.
19. A system for informing a home cellular telephone service region of a
cellular telephone network of a location of a customer having a cellular
telephone unit located proximate to a mobile data terminal in a foreign
cellular telephone service region of the cellular telephone network,
comprising:
means for automatically providing a first signal identifying the customer
from the mobile data terminal to a mobile data base radio station of a
mobile data network;
means for determining the foreign cellular telephone service region in
which the customer is located based upon a location of the mobile data
base radio station; and
means for transmitting data identifying the customer and the foreign
cellular telephone service region in which the customer is located from
the mobile data base radio station to the home cellular telephone service
region of the customer.
20. The system according to claim 19, wherein the means for determining
includes means for determining the identity of a foreign cellular
telephone service provider to which the customer has access.
21. The system according to claim 19, further comprising means for
automatically providing a second signal identifying the home cellular
telephone service region from the mobile data terminal to the mobile data
base radio station.
22. The system according to claim 21, wherein the first and second signals
are provided from the mobile data terminal immediately after the mobile
data terminal is turned on.
23. The system according to claim 19, wherein the data identifying the
customer and the foreign cellular telephone service region is transmitted
from a clearing house to the home cellular telephone service region.
24. The system according to claim 19, wherein the foreign cellular
telephone service region is determined through the use of a look-up table.
25. The system according to claim 19, wherein the cellular telephone unit
and the mobile data terminal are contained within an automobile.
26. The system according to claim 19, wherein the cellular telephone unit
and the mobile data terminal are integrated in a hand-carried, portable
unit.
27. The system according to claim 19, further comprising means for routing
a telephone call for the customer from the home cellular telephone service
region to the foreign cellular telephone service region.
28. The system according to claim 19, further comprising means for
transmitting a telephone number of a party calling the customer from the
home cellular telephone service region to the foreign cellular telephone
service region.
29. A system for informing a home cellular telephone service region of a
cellular telephone network of a location of a customer having a cellular
telephone unit electrically coupled to a mobile data terminal in a foreign
cellular telephone service region of the cellular telephone network,
comprising:
means for transmitting a first data signal identifying the foreign cellular
telephone service region in which the customer is located from the foreign
cellular telephone service region to the cellular telephone unit;
means for transmitting the first data signal from the cellular telephone
unit to the mobile data terminal;
means for transmitting, from the mobile data terminal to a mobile data base
radio station of a mobile data network, the first data signal, a second
data signal identifying the home cellular telephone service region of the
customer, and a third data signal identifying the customer; and
means for transmitting the first and third data signals from the mobile
data base radio station to the home cellular telephone service region of
the customer.
30. The system according to claim 29, wherein the means for transmitting
from the cellular telephone unit to the mobile data terminal includes
means for transmitting the identity of a foreign cellular telephone
service provider to which the customer has access.
31. The system according to claim 29, wherein the first, second and third
data signals are automatically transmitted immediately after the mobile
data terminal is turned on.
32. The system according to claim 29, further comprising:
means for transmitting the first, second and third data signals from the
base radio station to a clearing house; and
means for transmitting the first and third data signals from the clearing
house to the home cellular telephone service region.
33. The system according to claim 29, wherein the cellular telephone unit
and the mobile data terminal are contained within an automobile.
34. The system according to claim 29, wherein the cellular telephone unit
and the mobile data terminal are integrated in a hand-carried, portable
unit.
35. The system according to claim 29, further comprising means for routing
a telephone call for the customer from the home cellular telephone service
region to the foreign cellular telephone service region.
36. The system according to claim 29, further comprising means for
transmitting a telephone number of a party calling the customer from the
home cellular telephone service region to the foreign cellular telephone
service region. |
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Claims |
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Description |
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FIELD OF THE INVENTION
The present invention is a method and system for locating a cellular
telephone customer and, in particular, a method and system for locating a
cellular telephone user who is currently outside of the region in which
the user subscribes to cellular telephone service. The present invention
involves the use of a two-way mobile data terminal located proximate to
the cellular telephone.
BACKGROUND OF THE INVENTION
Cellular telephone service in the United States is provided by numerous
companies which provide service in separate geographical regions. The
Federal Communications Commission (FCC) has licensed two cellular carriers
in each Metropolitan Service Area (MSA) and Rural Service Area (RSA), of
which there are 306 and 428, respectively. The service area within each
individual region is divided into many distinct sub-regions, commonly
referred to as cells.
Each cell within a region contains a single cell-site control system (CSC),
which is composed of a processor, one or more radio receiver/transmitters,
and one or more radio antennas. The CSCs in a region are connected to a
network control system (NCS), which controls all cellular telephone
connections within that region. The NCS is, in turn, connected to one or
more wireline telephone company central offices (COs) in the region.
Each CSC is responsible for all customers having a cellular telephone
presently located in the corresponding cell. In particular, when a
cellular telephone is turned on, it may transmit a signal indicating that
it is ready to place and/or receive calls. This signal is received by CSCs
in the immediate area. The received signals are then fed to the NCS. The
CSC that receives the signal the strongest is generally the CSC that is
contained in the cell in which the cellular telephone is located. As such,
the NCS makes the particular CSC responsible for supporting calls
involving that cellular telephone.
If a call is placed or received by that telephone, the NCS transmits the
voice signals, as well as the data signals necessary for setting up and
controlling the voice signals, to the responsible CSC. The CSC sends a
data message to the mobile telephone, assigning that telephone an
unoccupied pair of frequencies in which signals are to be transmitted and
received (the transmitting frequency being different than the receiving
frequency). Thereafter, all of the signals transmitted during the cellular
phone call are handled by the responsible CSC on the assigned frequencies.
If, during a conversation, the cellular telephone, which may be located in
an automobile, for example, moves from one cell to another, signals may be
received stronger by the CSC in the new cell, in which case, the NCS may
make the CSC in the new cell responsible for that cellular telephone, and
the call in progress is handed-off to the new cell.
However, because different companies provide cellular telephone service to
the various regions throughout the United States, complications may arise
when a customer of a first company which services a first (home) region is
located in a second (foreign) region serviced by a second company
("roaming"). Some cellular carriers have entered into roaming agreements
pursuant to which they will provide service to each other's subscribers.
Indeed, the NCSs of the regions may, but need not, be connected to support
such conversations. As such, placing a call by a customer in a foreign
region may be as simple as dialing the area code and number. Calls
originated by the roaming subscriber are handled by the foreign systems,
and applicable charges are billed to the subscriber's home system
operator. Substantial premiums may apply to calls originated by roaming
subscribers.
However, problems arise in locating a customer in a foreign region
(serviced by a different company) so that calls can be received by the
customer. In a cellular telephone system having a "Standard Roaming"
feature, a party desiring to reach a customer in a foreign region must
know the particular foreign region in which the customer is located, which
of the two systems in the foreign region is providing service to the
roaming cellular telephone, and the access number of the NCS of the
service providing system in the foreign region. The party must then dial
the access number followed by the area code and local number in order to
call the customer.
In a cellular system having a "Follow Me Roaming".RTM. feature (registered
trademark of GTE Mobilnet), once a customer enters a foreign region, he
may press particular buttons on his cellular telephone in order to
activate Follow Me Roaming, i.e., he may transmit a signal to the nearest
CSC in order to notify the NCS in the foreign region and, in turn, the NCS
in the home region that he is presently located in the foreign region. A
party desiring to call the customer would then need to dial only the area
code and local number, because the home NCS knows to which foreign NCS to
route the call, i.e., the home NCS knows in which foreign region the
customer is located.
The customer must activate Follow Me Roaming in each new region into which
the customer travels by pressing the particular buttons on the cellular
phone. Inconvenience to the cellular telephone user arises because (a) the
subscriber must first know that he/she has, in fact, entered into a
foreign cellular service area, (b) the subscriber must manually activate
the Follow Me Roaming feature, and (c) when on an extended journey which
traverses many foreign cellular service areas, the subscriber must
continually be aware of his/her entering into a new area and must activate
the Follow Me Roaming feature again and again. Deactivation of Follow Me
Roaming is achieved by pressing other buttons on the cellular phone.
To eliminate this inconvenience on the customer, it is also known for a
cellular telephone to provide identification information (i.e., the I.D.
of the unit's home NCS) automatically, immediately after being turned on
in a foreign region. As in systems having Follow Me Roaming, the foreign
NCS then notifies the home NCS of the whereabouts of the customer,
allowing callers to dial only the local telephone number in order to reach
the customer. However, such a feature is not available in many regions of
the United States.
Moreover, when a call is forwarded to a cellular telephone subscriber in a
foreign region, the subscriber is charged for the air time and for the
long distance portion of the call, even if the subscriber receives an
unwanted ("nuisance") call.
SUMMARY OF THE INVENTION
The present invention provides a method and system for informing a company,
to the cellular telephone service of which a customer is a subscriber, of
the current location of the customer. The principles according to the
present invention may be applied, for example, in a situation where a
customer having both a cellular telephone unit and a mobile data terminal
in his automobile travels from the region which the subscribing company
serves (the home region) to another region (a foreign region).
In a first embodiment of the present invention, immediately after being
turned on, the mobile data terminal automatically transmits the customer
identification information (e.g., a telephone number stored in the mobile
data terminal), home region identification information (e.g., the data
system address for the data terminal of the subscriber company), and the
coded location of the nearest (mobile data) base radio station to the
nearest base radio station associated with the mobile data communications
network. Only once, at the time of cellular service initiation, this
identification information is programmed into a software application
program in the mobile data terminal. The coded location of the base radio
station is transmitted by the base radio station itself to the mobile data
terminal. Informing the mobile data terminal of this location information
simplifies the software resident in the mobile data terminal, although
such a transmission need not take place.
The base radio station may then transmit this identification information
and the coded location of the base radio station to a national clearing
house, which then uses a look-up table, for example, to determine the
foreign region in which the customer is currently located (based upon the
location of the particular base radio station). The clearing house then
transmits data identifying the customer and the foreign region to the
cellular NCS of the home region so that the customer can be reached by
simply dialing the customer's local telephone number. Alternatively, the
clearing house can be eliminated, in which case the information can be
transmitted directly from the base radio station to the NCS of the home
region, and the look-up operation can take place either in the mobile data
terminal or in the NCS of the home region.
In a second embodiment of the present invention, the mobile data terminal
is electrically coupled to the cellular telephone unit. Data identifying
the home region address and the foreign region is transmitted from the
cellular telephone unit to the mobile data terminal. This data, along with
data identifying the particular customer, is then automatically
transmitted to a clearing house via the nearest base radio station of the
mobile data system. The data identifying the particular customer and the
foreign region (including the particular service provider for that foreign
region) in which the customer is currently located is then transmitted
from the clearing house to the cellular NCS of the subscriber's home
region. Once again, the clearing house can be eliminated, and the
information can be transferred directly from the base radio station of the
mobile data system to the NCS of the home region. In this situation, the
mobile data terminal or the NCS of the home cellular system region could
perform any required processing of the information identifying the foreign
region.
In comparison to the above-described conventional features of a cellular
telephone system, a location service employing the principles according to
the present invention provides back-up and/or alternative capabilities
which may be more convenient for the cellular telephone subscriber.
Moreover, in another embodiment of the present invention, the subscriber
has the capability to reject nuisance calls, and thus avoid being charged
for such.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1(a) and 1(b) show a block diagram of the structure of two cellular
telephone regions.
FIG. 2 shows a block diagram illustrating the principles of a first
embodiment of the present invention.
FIG. 3 shows a block diagram illustrating the principles of a second
embodiment of the present invention.
FIG. 4 shows a block diagram illustrating the principles of an alternative
first embodiment of the present invention.
FIG. 5 shows an alternative location of a cellular telephone unit and
mobile data terminal.
DETAILED DESCRIPTION
Referring to FIG. 1, there is shown the structure of two cellular telephone
regions, i.e., a home region 102 and a foreign region 104. Home region 102
is divided into several cells 106. Foreign region 104 is similarly divided
into several cells 108.
The structure of the two regions, 102 and 104, is analogous, and,
therefore, for clarity purposes, generally only the foreign region 104
will be described. Each of the cells 108 of the foreign region 104
contains a CSC 110 which is connected to a NCS 112 of the region through a
wire 114, for example. The NCS 112 is, in turn, connected to a CO 116 of
the region through a wire 118, for example.
The CO 116 of the foreign region 104 is connected to the CO 120 of the home
region 102, over a voice line 122, for example, and the CO 120 of the home
region 102 is connected to an NCS 121 of the home region 102 in order to
allow customers in the foreign region 104 to be reached by parties in the
home region 102.
As shown in FIG. 1, a customer who has a cellular telephone unit 124 in his
automobile 126 and who subscribes to a cellular telephone service provided
by a home company in home region 102 travels to foreign region 104. In
particular, the customer is geographically located in cell 128 of foreign
region 104. If the customer desires to place or receive a cellular
telephone call, he must turn on the cellular telephone 124. Because, in
this case, the radio signals from the CSC 132 of cell 128 are the ones
that are the strongest received by the telephone 124, the customer will be
serviced by cell 128. Depending upon the particular features, if any,
available (as described above), it may be possible that identification
signals 130 from the telephone 124 may either be transmitted automatically
after the telephone 124 is turned on or transmitted upon the customer
pressing particular buttons on the telephone 124. NCS 112 may, in certain
cases, be able to notify NCS 121 of home region 102 that the particular
customer is presently located in foreign region 104.
Thereafter, if a party in home region 102 desires to place a call to the
customer, he may need to dial only the local telephone number of the
customer. Because NCS 121 knows that the customer is presently located in
foreign region 104, NCS 121 routes the call to CO 116 over line 122, and
then to NCS 112 over line 118. CO 116 then connects the call through to
telephone 124 via NCS 112 and CSC 132 through lines 118 and 134, which
carry both voice and data signals.
Referring now to FIG. 2, there is shown a block diagram illustrating the
principles of a first embodiment of the present invention. Similar to FIG.
1, a home region 102 and a foreign region 104 are shown in FIG. 2. The
automobile 126 in FIG. 2, however, not only contains a cellular telephone
unit 124, but also contains a mobile data terminal 202, which is used to
locate the telephone 124 in the cellular telephone system.
The mobile data terminal 202 is part of a mobile data network that may
extend throughout the United States, for example, the MOBITEX.RTM.
(registered trademark of Swedish Telecom) mobile data network manufactured
by Ericsson Mobile Communications AB. The mobile data network is used to
transmit data information, as opposed to voice information, between data
terminals throughout the United States. In the case of the U.S. Mobitex
system now under construction, the data is passed at a speed of 8,000 bits
per second over a frequency range of 896-901 MHz (from a mobile data
terminal) and 935-940 MHz (from a base radio station), for example.
The mobile data network includes many mobile data base radio stations (204,
206) that are contained in, and are responsible for, distinct areas (208
and 210, respectively) of the network, as shown by dashed lines in FIG. 2.
These mobile data base radio stations are the access nodes for the mobile
data terminals located in the corresponding areas. The mobile data base
radio stations are interconnected by a mobile data network.
Unlike the regions of a cellular telephone system, the areas of a national
mobile data network are serviced by a single company. As such, many of the
complications resulting from communication between regions in a cellular
telephone system are alleviated in a mobile data network. As illustrated
in FIG. 2, the regions of a cellular telephone system do not necessarily
correspond to the areas of a mobile data network.
The mobile data terminal 202 automatically notifies the data network when
it is switched on. Unlike in a cellular telephone system, the base radio
station used by the mobile data terminal is selected by the mobile data
terminal itself, not by the network. The particular base radio station is
selected based on the strength of the signals received from the base radio
stations. Each mobile data terminal constantly monitors the strength of
signal reception so that when it moves from an area covered by one base
radio station into an area covered by another, a signal is sent by the
terminal to the new base radio station, informing the network that all
subsequent data to the terminal should be routed through the new base
radio station.
The present invention provides various ways in which a mobile data terminal
can be used to provide the current location of a customer having a
cellular telephone contained in the same automobile, for example, when the
automobile is in a foreign region. It is assumed below that the customer
is a subscriber to both a cellular telephone service and a mobile data
service applying the principles according to the present invention.
In a first embodiment of the present invention, as illustrated in FIG. 2,
through the operation of application software the mobile data terminal 202
automatically transmits a data message over mobile data base radio station
204 and data line 214. The data message contains customer identification
information (e.g., the customer's cellular telephone number, which may be
preprogrammed into, and stored in, the data set of the mobile data
terminal), home region identification information (e.g., the mobile data
system address of the NCS of the subscriber company), and the coded
location of the mobile data base radio station 204 with which the mobile
data terminal 202 communicates. This coded location information is
provided by the mobile data base radio station itself in order to simplify
the software in the mobile data terminal 202. The data message is sent to
a national clearing house 212 or any other designated facility. Home
region identification information can be stored in the mobile data
terminal 202, or the clearing house 212 may instead use a look-up table,
for example, to determine the address of the company to which the
identified customer subscribes (based upon the customer's telephone
number).
In either situation, another look-up table, for example, may then be used
to correlate automatically (the identification number of) the particular
mobile data base radio station 204, from which the data was transmitted,
to the cellular telephone service region 104 (e.g., the city code) in
which the mobile data base radio station is physically located.
The clearing house 212 can then transmit the data identifying the customer
and the foreign region 104 in which the customer is currently located to
home region 102 (i.e., to the mobile data system address of the NCS 121 of
the subscriber company) in a short (economical) message over data line
216. In this manner, calls from home region 102 to the local telephone
number of the customer can be routed by the subscriber's home cellular
telephone company to foreign region 104 (i.e., to the foreign cellular
telephone company that services the city in which the customer is
currently located) in order to reach the customer, as described above.
It is to be understood that the determination of the foreign region based
upon the particular base radio station through the use of a look-up table
may instead be automatically performed in (the application software of)
the mobile data terminal, or manually or automatically performed in the
NCS of the home region itself, rather than in a clearing house. In such
situations, the use of a clearing house is not necessary, and the
identification information is transmitted directly from the mobile data
base radio station 204 to the NCS 121 of the home cellular telephone
region 102 over data network line 404, as shown in FIG. 4.
In a second embodiment of the present invention, the cellular telephone
unit 124 is electrically coupled to the mobile data terminal 202 over, for
example, a wire 302, as shown in FIG. 3. Referring simultaneously to FIGS.
1 and 3, mobile data terminal 202 receives, over wire 302, information
from the cellular telephone 124. In particular, the terminal 202 receives
information identifying the home cellular telephone region 102 in which
the customer is a subscriber, and the foreign cellular telephone region
104 in which the customer is currently located. This second piece of
information may be provided to the telephone 124 by the NCS 112.
The mobile data terminal 202 then transmits the data identifying the home
region and the current foreign region, as well as data identifying the
particular customer, to the clearing house 212 via the mobile data base
radio station 204. The clearing house 212 then transmits the data
identifying the foreign cellular telephone region 104 in which the
customer is located to the home cellular telephone region 102, via data
line 216. Once again, this enables the customer to be reached on the
cellular telephone 124 through the customer's local telephone number.
Once again, the clearing house may be eliminated, in which case the
identification information is transmitted directly from the base radio
station to the NCS of the home region, as shown in FIG. 4 with respect to
the first embodiment of the present invention. In such a situation, either
the mobile data terminal or the NCS of the home region can perform any
required processing of the information identifying the foreign region.
As shown in FIG. 5, the cellular telephone 502 and the mobile data terminal
504 may be hand-carried by the subscriber in a portable unit such as a
suitcase-like container 506, rather than being located in an automobile.
Depending upon the particular embodiment of the present invention being
implemented, the cellular telephone 502 may be electrically coupled to the
mobile data terminal 504 over a wire 508 and/or may be combined
(integrated) in a single device.
The present invention further provides that when a customer moves from an
area covered by a mobile data base radio station to an area covered by
another mobile data base radio station, but remains within the same
cellular system service region, logic may be used in the clearing house,
for example, to prevent such information from being transmitted to the NCS
of the home telephone service region. The home region needs to be informed
only when the customer moves into a different cellular telephone service
region. The logic therefore eliminates the transmission of these types of
unnecessary messages.
Moreover, in another embodiment of the present invention, when a party
places a call to the cellular telephone subscriber, the NCS of the home
region first formats and sends a mobile data message to the subscriber's
mobile data terminal that displays the telephone number of the calling
party. The cellular telephone subscriber then has the option of accepting
or rejecting the call by pressing an appropriate key on the mobile data
terminal that, in turn, sends an accept or reject message back to the NCS.
In this manner, the cellular telephone subscriber has the capability to
reject nuisance calls, and thus avoid air time and long distance charges
for such calls.
The principles of the present invention may also be applied to a telephone
system that supports a "single number" service. The single number service
provides a subscriber with one telephone number associated with the
subscriber himself, as opposed to the specific telephone that he is
currently using (as is commonly done). To call a subscriber of this
service, the personal number of that subscriber is dialed into the
telephone network. The telephone company, which provides the single number
service and which must be aware of the present location of the subscriber,
directs the call to whereever the person is via whatever communication
service (e.g., cellular telephone service) the subscriber is currently
using.
In particular, in an embodiment of the present invention, a "gateway",
which includes software-controlled switches and other circuitry, couples
the telephone network to a mobile data network. Through utilizing the
principles | | |
