Telephone system and method with background location response capability

A portable telephone capable of background location transmission response, and methods which can be executed by such a telephone or a system using such a telephone. In one such portable telephone, a position locator which, in response to a location request signal, can determine the location of the portable telephone and generate a corresponding location signal. A receiver receives an incoming call signal and an incoming location request signal. A user interface has: an audio or visual user output device which can reproduce audio or visual information in an incoming call signal as a corresponding audio or visual display; and an audio user input device which generates an audio output signal corresponding to a user's voice. An alert generator which, in response to a received incoming call signal, generates a first physical characteristic to indicate an incoming call to a user of the portable telephone. A location request detector which, in response to a received location request signal, can direct the location request signal to the position locator without activating the alert generator. A transmitter to transmit a location signal generated by the position locator in response to a received location request signal, and to transmit the audio output signal.

FIELD OF THE INVENTION 
The present invention relates to apparatus, systems and methods, which 
allow a location of a portable telephone to be obtained from a remote 
location in a background operation mode. 
BACKGROUND OF THE INVENTION 
Portable telephones, particularly in the form of current cellular 
telephones, are well known. In addition, several companies have disclosed 
and are proceeding with plans for a network of low-orbiting satellites 
which will allow communication from portable telephones from almost 
anywhere in the world, without relying on the multiple call regions or 
"cells" in a cellular telephone system. Portable devices which allow a 
user to determine their location particularly based on various satellite 
positioning systems, are also now known. Such systems are generally 
referred to as Global Positioning Systems ("GPS"). These systems use 
signals from a series of satellites which allow a portable receiver (i.e. 
a GPS receiver) on earth to determine its position with a fairly high 
degree of accuracy. 
It is often desirable for one individual to know the location of another. 
It would be desirable if a first person can conveniently find the location 
of a second person who might be carrying a portable telephone, without the 
first person having to call the second person on the portable telephone 
and interrupt the second person. For example, the second person might be 
in a meeting and would not consider it convenient to even have a first 
person call them just to ask where they are, although they might still 
like to receive on their portable telephone calls for other purposes. Of 
course, the second person would have no way of knowing whether a call to 
their portable telephone was for some important reason (e.g. a business 
call) or just a call from a relative or friend to ask where they are and 
when they might be home. 
SUMMARY OF THE INVENTION 
The present invention provides a means by which individuals can obtain the 
location of a portable telephone user by providing the portable telephone 
with a position locator, such as GPS receiver. The present invention 
further recognizes that in many situations it is desirable that the 
portable telephone user not be disturbed to answer a call just to report 
their location to a spouse, friend, or the like. Therefore, the present 
invention provides a means by which the portable telephone user can 
continue to receive other calls to their portable telephone as usual. 
Further, the present invention provides a means by which calls for 
location requests only can be directly routed to a position locator on the 
portable telephone, and the location information automatically supplied to 
the caller from the position locator on the portable telephone, all 
without disturbing the portable telephone user. 
In accordance with one aspect of the invention then, there is provided a 
portable telephone capable of background location transmission response, 
comprising: 
a) a position locator which, in response to a location request signal, can 
determine the location of the portable telephone and generate a 
corresponding location signal; 
b) a receiver to receive an incoming call signal and an incoming location 
request signal; 
c) a user interface having: 
an audio or visual user output device which can reproduce audio or visual 
information in an incoming call signal as a corresponding audio or visual 
display; and 
an audio user input device which generates an audio output signal 
corresponding to a user's voice; 
d) an alert generator which, in response to a received incoming call 
signal, generates a first physical characteristic to indicate an incoming 
call to a user of the portable telephone, 
e) a location request detector which, in response to a received location 
request signal, can direct the location request signal to the position 
locator without activating the alert generator; 
f) a transmitter to transmit a location signal generated by the position 
locator in response to a received location request signal, and to transmit 
the audio output signal. 
In another aspect of the present invention, there is provided a telephone 
system capable of providing data communication between any of a plurality 
of first telephones and a remote portable telephone, and capable of 
location response, comprising: 
a) a portable telephone having: 
(i) a position locator which can determine the location of the portable 
telephone and generate a corresponding location signal; 
(ii) a receiver to receive an incoming location request signal; 
(iii) a user interface having: 
an audio or visual output device which can reproduce audio or visual 
information in an incoming call signal as a corresponding audio or visual 
display; and 
an audio user input device which generates an audio output signal 
corresponding to a user's voice; 
(iv) a location request detector which, in response to a received location 
request signal, can direct the location request signal to the position 
locator; and 
(v) a transmitter to transmit a location signal generated by the position 
locator in response to a received location request signal; 
b) a centralized base station having: 
(i) means for receiving from any calling one of the plurality of first 
telephones, an incoming location request signal; 
(ii) a transceiver to transmit an incoming location request signal to the 
portable telephone, and to receive a location signal from the portable 
telephone; 
(iii) a location identification means for determining the location of the 
calling one of the first telephones from a caller identification carried 
by the incoming signal; 
(iv) a comparator for determining the distance between the location 
received from the portable telephone and the location of the calling one 
of the first telephones, and generating a resulting distance signal or 
estimated travel time signal; and 
(v) means for forwarding the distance signal or estimated travel time 
signal to the calling one of the first telephones or the portable 
telephone. 
In a still further aspect of the present invention, there is provided a 
method of communicating with a portable telephone and obtaining a 
background location transmission response from the portable telephone, 
comprising: 
a) communicating a call signal from a first telephone to a centralized base 
station through a first network through which any of a plurality of first 
telephones can communicate with the centralized base station; 
b) transmitting an incoming call signal received from a first telephone at 
the base station, from the centralized base station to the portable 
telephone; 
c) activating an alert generator on the portable telephone in response to 
the received incoming call signal, so as to generate a first physical 
characteristic to indicate an incoming call to a user of the portable 
telephone; 
c) transmitting an audio output signal corresponding to a user's voice, 
form the portable telephone to the centralized base station; 
d) communicating a location request signal from a first telephone through 
the first network to the centralized base station; 
e) transmitting an incoming location request signal received from a first 
telephone at the base station, from the centralized base station to the 
portable telephone; 
f) receiving the location request signal at the portable telephone; 
g) directing the location request signal to a position locator on the 
portable telephone without activating the alert generator, which position 
locator can determine the location of the portable telephone and generate 
a corresponding location signal; 
c) transmitting the location signal from the portable telephone to the 
centralized base station; 
d) communicating location information corresponding to the location signal, 
from the centralized base station to the first telephone which 
communicated the location request to the base station. 
The present invention then, provides a convenient means by which an 
individual can obtain the location of a user of a portable telephone 
automatically and without disturbing that user by requiring them to answer 
a call just for their location. The alert generator on the portable 
telephone which signals a user of a normal incoming telephone call, is 
bypassed automatically upon detection of a location request signal and the 
position locator communicates the position information also automatically 
to the caller. Further, the present invention additionally provides means 
by which a street location and/or the distance between the caller and the 
portable telephone user can also be automatically reported to the caller, 
rather than just other location information (such as geographic location 
only) which might be generated by the position locator on the portable 
telephone.

EMBODIMENTS OF THE INVENTION 
Referring first to FIG. 1, the apparatus shown includes a first telephone 
10, having a typical handset 12 with both an earphone for audio output and 
a microphone for a user audio input (in particular, a voice input). A 
keypad 14 provides a means for dialing in the usual fashion. First 
telephone can communicate over a line 2 to a telephone exchange 16. Other 
lines 4 and 6 allow other telephones the same or similar to first 
telephone 10, to communicate with the exchange 16. Line 18 allows 
communication between the telephone exchange 16 and a centralized base 
station 17. Lines 2, 4, 6, 8 and exchange 16 form a first network through 
which multiple first telephones can communicate with the centralized base 
station 17. While the particular first telephone 10 is shown connected by 
a line 2, it will be understood that one or more of lines 2, 4, 6, or 8 
could instead be cableless connections such as radio or satellite 
connections. For example, first telephone 10 itself could be a portable 
telephone. At the exchange 16, any particular first telephone 
communicating with the exchange 16 is identified by its connection and a 
caller identification code ("caller ID code"), in the form of a first 
network address (e.g. the telephone number of that phone) is added to a 
calling signal routed through exchange 16. Alternatively, the caller ID 
code could be entered into keypad 14 of first telephone or spoken into 
handset 12 (and interpreted by suitable voice recognition software on 
processor 20). 
With the standard keypad 10, a first telephone can communicate through the 
first network with other phones, both portable and stationary. For the 
sake of simplicity only one exchange 16 is shown between first phone 10 
and centralized base station 17, but others could be present. In the 
present invention, when a user at first phone 10 wishes to reach a 
portable telephone, they enter in keypad 14 the network address (that is, 
the phone number) of that portable telephone in the usual manner. Exchange 
16 is programmed to recognize the class of phone numbers to which a dialed 
portable phone belongs, as one which is to be routed to centralized base 
station 17. This can be accomplished by having all such portable phone 
numbers start with a given numerical sequence, such as "222". In addition, 
once a first telephone is connected to centralized base station 17, but 
before centralized base station 17 contacts the portable phone whose 
number was dialed by a first telephone, the keypad 14 can be used to enter 
a predetermined location request signal in the form of a further code, 
such as "**" or any other preselected alphanumeric combination on keypad 
14. 
Centralized base station 17 includes a router 18 which receives incoming 
calls and incoming location request signals from any phone on the first 
network. Router 18 is capable of waiting a preselected time following 
receipt of an incoming call from a first telephone, to ascertain whether 
there is also a received location request signal. If no location request 
signal is received, router 18 will connect the caller through 
transmitter/receiver the portable telephone 28 whose number was dialed at 
a first telephone. If a location request signal is received within the 
preselected time, router 18 will first direct the received caller 
identification to a suitably programmed processor 20, which has access to 
a caller ID database 22 and a map database 24. Caller ID database 22 
contains data correlating phone numbers of fixed telephones (that is, 
telephones which are not portable and tend to remain in a fixed location) 
in a given geographic region (for example, within a fixed radius of base 
station 17) with geographic locations. Map database contains a street map 
correlated with geographic co-ordinates. Router 18 and processor 20 are 
further suitably programmed to execute the steps of the methods disclosed 
below. 
A typical portable telephone 28 has a housing 29 within which are provided 
the necessary electronics, as well as a power supply compartment to hold a 
battery. Such telephones, including battery are typically less than 10 
pounds in weight, and often less than 5 or even 2 pounds, and currently 
even less than 1 pounds. The battery itself is usually less than 2 or 1 
pounds, or currently less than 0.5 pounds. Further, they are usually less 
than 6 inches by 3 inches in length and width and less than 1 inch in 
thickness. Portable telephone 28 also has an audio input device 38 in the 
form of a microphone, a keypad 37 similar in operation to keypad 14 of 
first telephone 10, and an audio-visual display device 36 which includes 
an audio output in the form of earphone 36b and liquid crystal display 
("LCD display") 36a. An antenna 30 allows transmission and reception with 
remote locations such as centralized base station 17, and also receives 
signals for a GPS location detector 40. A user call alert 34 in the form 
of small speaker and associated driver circuitry, provides a user with a 
first physical characteristic in the form of an audible first alert 
indicating an incoming call signal. A user location alert 35 in the form 
of a light (such as an LED) and associated circuitry, illuminates to 
provide a user with a second physical characteristic preferably different 
from the first physical characteristic, for example in the form of a 
visible indication of an incoming location request signal, and remains 
illuminated while a location request is being processed and transmitted. 
Alternatively, user location alert 35 could be a vibrator which alerts a 
user by means of a vibration of portable phone 28 when it is near the 
user's body. By a user entering an appropriate sequence of characters on 
keypad 37 (such as "###") the keypad 37 can also act as a bypass switch 42 
which in one position causes an incoming location request signal to not 
only illuminate the light of user location alert 35, but also causes call 
alert 34 to sound. Re-entry of the same character sequence on keypad 37 
causes bypass switch 42 to return to its normal setting in which an 
incoming location request signal activates only the light of user location 
alert 35, and not the audible alarm provided by the speaker of user call 
alert 34. An alert switch indicator 43, in the form another LED ("light 
emitting diode") indicates which position bypass switch 42 is in. 
Referring to FIG. 2, a schematic of the components of portable telephone 28 
is provided. Most of the functions of portable telephone 32 are executed 
by processor 32. Processor 32 is a digital microprocessor suitably 
programmed to execute the methods performed by portable telephone 32 as 
described herein. However, it will be appreciated throughout this 
application that processor 32 or any hardware or software described in any 
of the components of the present application, can be replaced by 
equivalent hardware and/or software to perform the necessary functions. 
Processor 32 uses a main storage 48 in which the necessary programming 
code is stored and for purposes described below. Main storage 48 and any 
other storage device, can be a magnetic or optical disk drive, but is 
preferably a solid state storage device. A location code storage 50, which 
may or may not be the same device as main storage 48, stores the data 
identifying a received sequence of alphanumeric characters as a location 
request signal. A timer 52 provides a timing signal to processor 32 to 
obtain the necessary timing functions described herein. Portable telephone 
28 further includes a transmitter/receiver combination ("transceiver") 46 
connected to antenna 30. 
As mentioned, portable telephone 28 includes a GPS location detector 40. 
GPS location detector uses signals from any series of positioning 
satellites, to ascertain the geographical location of portable telephone 
28, and generates a corresponding location signal for transmission. 
The operation of the telephone system of FIGS. 1 and 2 will now be 
described, particularly with reference to the flowchart of FIG. 3. First, 
it will be assumed that portable telephone 28 is not in use (i.e. it is 
not being used for any type of communication). An individual at a first 
telephone 10 can communicate with portable telephone 28 or any other 
similar portable telephone, by dialing the network access code 
(specifically, the pre-assigned telephone number) of that portable 
telephone on keypad 14 after lifting handset 12. The exchange 16 of the 
first network will then direct the call to centralized base station 17. 
Router 17 of centralized base station will receive (200) the incoming call 
data from the caller at first telephone 10. The caller ID (telephone 
number of calling first telephone 10) is also received by router 18 and 
held temporarily in a memory. Router 18 is programmed to wait a preset 
time (such as 1 to 2 seconds, or less than 10 or 30 seconds) after 
connecting with first telephone 10 to see if a location request code (such 
as the "**" mentioned earlier) is then received (202). If no location 
request code is received within the preset time, the incoming call data 
(in the form of a normal incoming call alert) is transmitted (210) through 
transceiver 26 to the portable telephone 28 whose telephone number was 
dialed by the individual at first telephone 10. If the user of portable 
telephone 28 chooses to answer that call by pressing an appropriate button 
on keypad 37, the individual at the calling first telephone 10 and the 
user at portable telephone 28 (the "caller") can then be connected to 
engage in an audio conversation in the normal manner. That is, the user 
will be able to hear the audio information from caller through earphone 
36b and respond to speaking into microphone 38. In addition or 
alternatively, the user can see data sent from a caller on LCD screen 36a. 
Alternatively, when router 18 receives an incoming call from first 
telephone 10, a voice synthesizer 10 under control of processor 20, may 
transmit to the calling first telephone 10, a synthesized voice message to 
the effect that if only the called number's current location is required, 
the location request code should now be entered (which the voice 
synthesizer will state is "**", for example) and that the call will 
otherwise be transmitted to the dialed portable telephone if no such code 
is entered within the predetermined time. Router 18 then waits to see if 
the location request code is then entered with the predetermined time 
(202) and proceeds to transmit the call (210) as before, if the location 
request code is not received within the predetermined time. 
In either of the foregoing situations, the caller can either self-initiate 
entry of a re-location request code or the caller can be given such option 
with appropriate instructions, acting through processor 20 and voice 
synthesizer. A re-location request code allows the caller to automatically 
receive updates on the portable telephone's location. These can be at 
fixed time intervals or at time intervals determined by the caller by 
entering further data on keypad 14 of first telephone 10 preferably under 
voice synthesized instructions from processor 20 and voice synthesizer 19. 
For example, the re-location request code would be a "#" sign entered on 
keypad 14 followed by a number indicating the time interval (e.g. every 20 
minutes) and total elapsed time (e.g. three hours) during which automatic 
re-location is requested. Alternatively, the caller can request that they 
be notified when portable telephone 28 reaches a destination location 
either identified by the caller through keypad 14 or by voice through 
handset 12, in which case appropriate voice recognition software will be 
executed by processor 20. 
If router 18 does receive a location request code within the predetermine 
time, then processor 20 is notified which determines the caller ID (that 
is, the telephone number of the calling first telephone 10) from router 20 
(204). Processor 20 uses caller ID database 22 to then determine the 
location of the individual (the "caller") at the calling first telephone 
10 (206). This location is stored in caller ID database as a street 
address. By a "street address" is meant information identifying a caller's 
location by reference to one or more objects (whether natural, or 
artificial such as a street, city, county or the like name), such as one 
or more street names and optionally a house number, or the like. Processor 
20 uses map database 24 to determine (208) the geographic location (that 
is, the latitude and longitude co-ordinates) of the calling first 
telephone 10. The incoming call, in particular the incoming call data in 
the form of an incoming location request code and optionally a re-location 
request code, is then transmitted (210) to the called portable telephone 
28. It should be noted that it is not essential that the location request 
code transmitted from centralized hub 17 need not be the same code 
received from calling first telephone 10. However, for simplicity of 
discussion, it will be assumed below that they are the same. 
When an incoming call signal is received by transceiver 46 of portable 
telephone 28 (212) it is checked by processor 32 (214) to see if the data 
in the call signal (that is, the incoming call data) contains a location 
request code and, if so, does it also contain a re-location request code. 
If there is no location request code, the user call alert 34 is activated 
(226). Processor 32 then waits a predetermined time while maintaining user 
call alert 34 active, to see if the user of portable telephone 28 chooses 
to answer the incoming call (228). If the user of portable telephone 28 
then chooses to answer the call by pressing an appropriate key on keypad 
37, within the predetermined time, the caller is connected to portable 
telephone 28 for two-way communication (230) as described above. If the 
user does not answer the incoming call within the predetermined time or, 
after connection either the user or the caller terminates the 
communication, the caller is disconnected (222). If either of these two 
events occurs, router 18 at centralized base station 17 also disconnects 
the caller from base station 17. Since there was no location request code, 
processor 32 assumes that there can be no automatic re-location activated 
(224) and the method has reached it's end until another incoming call is 
received. 
If the processor 32 determines (214) that the incoming call signal received 
by transceiver 46 does contain a location request code, processor 32 then 
sends (215) a location request signal to GPS location detector 40 without 
activating user call alert 34. A first location signal, corresponding to 
the geographical location of portable telephone 38 as determined by GPS 
location detector 40, is forwarded to processor 32 for transmitting by 
transceiver 46 back to the centralized base station 17 from which the 
location request code was received (216). No further communication is 
required between portable telephone 28 and centralized base station 17 at 
this time and their connection can be terminated. If no re-location 
request code was found in the incoming call data by processor 32, no 
automatic re-location is activated (224) and another further happens at 
portable telephone 28. If a re-location request code was found (224), and 
if the re-location request code requested location reports at 
predetermined time intervals, processor 32 checks (232) through timer 52 
whether the total elapsed time has been exceeded and, if so, the routine 
is brought to the END. If not, processor 32 continues to wait for the 
predetermined time interval to elapse (234) and when it does, the location 
from GPS location detector is again transmitted to base station 17 as 
further location signals. This cycle then continues until the 
predetermined elapsed time has been exceeded. Of course, each time the 
location is communicated (216) to base station 17, communication with base 
station 17 can then be terminated until the predetermined time interval 
has again elapses (or until there is another incoming or outgoing call at 
portable telephone 38). Alternatively, if the re-location request signal 
as determined by processor 32, contained a request for further location 
reports until a specified destination location is reached, processor 32 
will determine from GPS location detector when that specified location is 
reached (232) and the cycle will END at that time, rather than a 
predetermined total elapsed time. 
Meanwhile, back at base station 17, a first location signal is received 
within at most, one or two seconds after the corresponding location 
request data was transmitted from transceiver 26. Using the location 
information in this first location signal, which will specify a geographic 
location, processor 20 at base station 17 can execute one or more of a 
number of alternatives (218) depending on how it has been programmed 
and/or instructed from calling first telephone 10. For example, processor 
20 can use the location information and map database 24 to determine a 
street address of a called portable telephone 28 from which a location 
signal has been received. Alternatively, the geographic location of 
portable telephone 28 and the previously determined geographic location of 
calling first telephone 10 (based on received caller ID, as discussed 
above) can be used by processor 20 to calculate the distance between 
called portable telephone 28 and calling first telephone 10. This distance 
can be a straight line distance or the distance based on the shortest road 
route using map database 24. Further travel time can be estimated between 
the location of called portable telephone 28 and calling first telephone 
10. Any or all of these items of information can be forwarded (220) to the 
calling first telephone 10 from processor 20 to appear as data on a 
suitable LCD display screen on first telephone 10 (not shown) or using 
voice synthesizer 19 to provide the information as an audio output to 
calling first telephone 10. When the information has been forwarded, 
router 18 can disconnect (222) the calling first telephone. If further 
location signals are received automatically from called portable telephone 
28 as a result of a re-location request code from calling first telephone 
10, router 18 can upon receipt of such signals automatically dial the 
calling first telephone 10, perform the necessary distance/street address 
determinations discussed above (218) and forward (220) any of the same 
foregoing information items for the new received location of called 
portable telephone 28. 
It will be appreciated that instead of a called portable telephone 28 
keeping track of re-location requests automatically, as described in 
detail above in connection with the drawings, this can be done instead at 
processor 20 of centralized base station 17. In this variation, each time 
a location signal is received from called portable telephone 28, 
communication is then terminated until the elapsed interval has passed, at 
which point base station 17 calls the called portable telephone 28 again 
and a new location request code is sent from base station 17 to the called 
portable telephone 28. Thus in the drawings, following step (234) (which 
occurs at centralized base station 17 in this variation), step (210) is 
executed at the base station and the cycle is from there to END. 
Thus, it will be seen that the present invention enables retrieval of a 
portable phone's location from any other telephone, without disturbing the 
portable phone's user (this is sometimes referenced as a background 
operation mode). Further, the invention allows automatic updates of 
locations to be sent to a caller all again without disturbing the portable 
phone's user. However, the user can bypass any background operation by 
means of bypass switch 42, ensuring that no locations are transmitted 
without the user being alerted by user call alert 34 and then allowing the 
user to answer the call on the user interface if desired. Bypass switch 42 
can further also allows the user to completely deactivate background 
operation so that received incoming calls carrying only a location request 
code will be automatically disconnected without GPS location detector 40 
providing a location signal. It will also be appreciated that the present 
invention could be applied to other communication devices than telephones. 
For example, instead of a portable telephone a portable communication 
device, such as a pager could be used. Similarly, any of first telephones 
10 could be replaced by another communication device. 
Variations and modifications to the above described embodiments are, of 
course, possible. Accordingly, the present invention is not limited to the 
embodiments described above.