U.S. patent application number 09/921971 was filed with the patent office on 2002-02-07 for method and apparatus for providing reserve power in a cellular telephone.
This patent application is currently assigned to SnapTrack, Inc.. Invention is credited to Sheynblat, Leonid, Wolf, Thomas George.
Application Number | 20020016189 09/921971 |
Document ID | / |
Family ID | 22327863 |
Filed Date | 2002-02-07 |
United States Patent
Application |
20020016189 |
Kind Code |
A1 |
Sheynblat, Leonid ; et
al. |
February 7, 2002 |
Method and apparatus for providing reserve power in a cellular
telephone
Abstract
Reserve power is provided in a portable cellular transceiver
comprising a Global Positioning System (GPS) receiver by monitoring
a power level of a battery of the portable cellular transceiver
using a power detection circuit. A comparator circuit determines
whether the power level of the battery is greater than a
predetermined threshold. Based on the available power level, a
power control circuit automatically places the transceiver into at
least one low power mode when the power level reaches a
corresponding threshold level. The low power mode selectively
powers down circuitry of the portable cellular transceiver. The
corresponding threshold level reserves power for an emergency
telephone call. Power is provided to the circuitry of the portable
cellular transceiver when the available power level is greater than
the predetermined threshold. The reserve power provides power for
the activation of the portable cellular transceiver, establishment
of a call between the portable cellular transceiver and a cellular
base station, transfer of GPS satellite acquisition aiding
information to the portable cellular transceiver, receipt of GPS
satellite information, communication of GPS satellite information
to the cellular base station, and determination of a position of
the portable cellular transceiver. The emergency telephone call may
be a single button enhanced 911 call.
Inventors: |
Sheynblat, Leonid; (Belmont,
CA) ; Wolf, Thomas George; (Mountain View,
CA) |
Correspondence
Address: |
James C. Scheller, Jr.
BLAKELY, SOKOLOFF, TAYLOR & ZAFMAN LLP
Seventh Floor
12400 Wilshire Boulevard
Los Angeles
CA
90025-1026
US
|
Assignee: |
SnapTrack, Inc.
|
Family ID: |
22327863 |
Appl. No.: |
09/921971 |
Filed: |
August 2, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09921971 |
Aug 2, 2001 |
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|
09109478 |
Jul 2, 1998 |
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6314308 |
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Current U.S.
Class: |
455/574 ;
455/572 |
Current CPC
Class: |
G01S 19/17 20130101;
Y02D 70/164 20180101; G01S 19/05 20130101; G01S 19/09 20130101;
H04W 52/0296 20130101; G01S 5/145 20130101; Y02D 30/70 20200801;
G01S 2205/008 20130101; G01S 19/34 20130101; H04W 52/0277 20130101;
G01S 2205/006 20130101 |
Class at
Publication: |
455/574 ;
455/572 |
International
Class: |
H04M 001/00 |
Claims
What is claimed is:
1. A method for providing reserve power in a portable communication
device, the method comprising the steps of: monitoring a power
level of a battery of the portable communication device; and
automatically placing the portable communication device into at
least one low power mode when the power level reaches at least one
threshold level, wherein the at least one threshold level reserves
power for at least one emergency communication message.
2. The method of claim 1, wherein the portable communication device
comprises a portable cellular transceiver, wherein the portable
cellular transceiver comprises a satellite positioning system (SPS)
receiver.
3. The method of claim 2, wherein the SPS receiver comprises a
Global Positioning System (GPS) receiver and wherein once said
portable communication device is placed in said at least one low
power mode, said portable communication cannot be used to
communicate except for said at least one emergency communication
message thereby preserving power in said battery for said at least
one emergency communication message.
4. The method of claim 1, further comprising the steps of:
determining if a power level of the battery is greater than a
predetermined threshold; and providing power to at least one
circuit of the portable communication device when the power level
is greater than a predetermined threshold.
5. The method of claim 1, wherein the at least one emergency
communication message is an enhanced 911 call, wherein the reserve
power allows for: activation of the portable communication device;
establishment of a call between the portable communication device
and a cellular base station; receipt of GPS signals; and
communication of GPS satellite information to the cellular base
station.
6. The method of claim 5, wherein the reserve power further allows
for: transfer of GPS satellite acquisition aiding information to
the portable communication device; and determination of a position
of the portable communication device.
7. The method of claim 5, wherein the reserve power further allows
for determination of a position of the portable communication
device.
8. The method of claim 5, wherein the GPS satellite information
comprises at least one of GPS pseudorange information, digitized
signals from which GPS pseudorange information can be determined,
and latitude and longitude information.
9. The method of claim 1, wherein the at least one emergency
communication message is an emergency 911 call, wherein the reserve
power allows for: activation of the portable communication device;
establishment of a high power call between the portable
communication device and at least three cellular base stations,
wherein the at least three cellular base stations determine the
location of the portable communication device using a network
overlay approach, wherein the network overlay allows for a
determination of the location using a time of arrival of the signal
at the at least three cellular base stations.
10. The method of claim 1, wherein the at least one emergency
telephone call is a single button call, wherein one button of the
portable communication device enables the emergency communication
message.
11. The method of claim 1, wherein the at least one low power mode
selectively powers down circuitry of the portable communication
device.
12. The method of claim 1, wherein the at least one low power mode
selectively disables capabilities of the portable communication
device.
13. The method of claim 1, further comprising the step of
predicting the time at whith the portable communication device will
be placed into the at least one low power mode.
14. The method of claim 1, wherein a single button of the portable
communication device provides the at least one emergency
communication message, wherein activation of the single button
results in: selective application of power to GPS receiver
circuitry, wherein a position information of the portable cellular
transceiver is determined; selective application of power to
communication circuitry, wherein the position information of the
portable communication device is transmitted along with an
emergency message to an emergency operator.
15. The method of claim 14, wherein the emergency message comprises
voice data.
16. The method of claim 14, wherein the emergency message comprises
an alphanumeric message, the alphanumeric message comprising the
identification and location of the user.
17. The method of claim 14, wherein the emergency message comprises
voice data and alphanumeric data, wherein the alphanumeric data
comprises position information of the user.
18. A method for providing reserve power in a portable cellular
telephone comprising a position circuit, the method comprising the
steps of: monitoring a power level of a battery of the portable
cellular telephone; and automatically placing the portable cellular
telephone into at least one low power mode when the power level
reaches at least one threshold level, wherein the at least one
threshold level reserves power for at least one emergency telephone
call.
19. The method of claim 18, wherein the at least one emergency
telephone call is a single button enhanced 911 call, wherein
activation of the single button enables the reserve power, the
enabled reserve power: activating the portable cellular telephone;
establishing a call between the portable cellular telephone and a
cellular base station; receiving signals to perform a positioning
operation; and communicating position information to the cellular
base station.
20. The method of claim 19, wherein the enabled reserve power is
used to determine a position information of the portable cellular
telephone.
21. The method of claim 19, wherein the position information
comprises at least one of pseudorange information, digitized
signals from which pseudorange information can be determined, and
latitude and longitude information.
22. The method of claim 18, wherein a single button of the portable
cellular telephone provides the at least one emergency telephone
call, wherein activation of the single button results in: selective
application of power to the position circuit, wherein a position
information of the portable cellular telephone is determined;
selective application of power to communication circuitry, wherein
the position information of the portable cellular telephone is
transmitted along with an emergency message to an emergency
operator.
23. A portable cellular transceiver comprising a Global Positioning
System (GPS) receiver, the portable cellular transceiver
comprising: a power detection circuit coupled to a battery, the
power detection circuit monitoring a power level of the battery of
the portable cellular transceiver; and a power control circuit
coupled to at least one transceiver circuit of the portable
cellular transceiver for automatically placing the portable
cellular transceiver into at least one low power mode when the
power level reaches at least one threshold level, wherein the at
least one threshold level reserves power for at least one emergency
telephone call.
24. The portable cellular transceiver of claim 23, wherein the
power detection circuit monitors a power level of the battery.
25. The portable cellular transceiver of claim 23, further
comprising a comparator circuit for determining if a power level of
the battery is greater than a predetermined threshold, wherein the
power control circuit provides power to at least one circuit of the
portable cellular transceiver when the power level is greater than
a predetermined threshold.
26. The portable cellular transceiver of claim 23, wherein the at
least one emergency telephone call is a single button enhanced 911
call, wherein activation of the single button enables the reserve
power, the enabled reserve power providing power for: activation of
the portable cellular transceiver, wherein the portable cellular
transceiver comprises telephone circuitry and GPS receiver
circuitry; establishment of a call between the portable cellular
transceiver and a cellular base station; transfer of GPS satellite
acquisition aiding information to the portable cellular
transceiver; receipt of GPS signals; and communication of position
information to the cellular base station.
27. The portable cellular transceiver of claim 26, wherein the
enabled reserve power further provides power for transfer of GPS
satellite acquisition aiding information to the portable cellular
transceiver.
28. The portable cellular transceiver of claim 26, wherein the
enabled reserve power further provides power for determination of a
position of the portable cellular transceiver.
29. The portable cellular transceiver of claim 26, wherein the
position information comprises at least one of GPS pseudorange
information, digitized signals from which GPS pseudorange
information can be determined, and latitude and longitude
information.
30. The portable cellular transceiver of claim 23, wherein the at
least one emergency telephone call is an emergency 911 call,
wherein activation of the single button enables the reserve power,
the reserve power providing power for activation of the portable
cellular transceiver; establishment of a high power call between
the portable cellular transceiver and at least three cellular base
stations, wherein the at least three cellular base stations
determine the location of the portable cellular transceiver using a
network overlay approach, wherein the network overlay allows for a
determination of the location using a time of arrival of the signal
at the at least three cellular base stations.
31. The portable cellular transceiver of claim 23, wherein the at
least one low power mode selectively powers down circuitry of the
portable cellular transceiver, wherein a single button of the
portable cellular transceiver provides the at least one emergency
telephone call, wherein activation of the single button results in:
selective application of power to GPS receiver circuitry, wherein a
position information of the portable cellular transceiver is
determined; and selective application of power to communication
circuitry, wherein the position information of the portable
cellular transceiver is transmitted along with an emergency message
to an emergency operator.
32. The portable cellular transceiver of claim 31, wherein the
emergency message comprises identification and position information
of a user.
33. A hand-held cellular telephone system comprising a Global
Positioning System (GPS) receiver, wherein the system comprises: a
power detection circuit coupled to a battery for monitoring a power
level of the battery of the hand-held cellular telephone system;
and a power control circuit coupled to a transceiver circuit of the
portable cellular transceiver for automatically placing the
hand-held cellular telephone system into at least one low power
mode when the power level reaches at least one threshold level,
wherein the at least one threshold level reserves power for at
least one call to an emergency operator.
34. The hand-held cellular telephone system of claim 33, further
comprising a comparator circuit for determining if a power level of
the battery is greater than a predetermined threshold, wherein the
power control circuit provides power to at least one circuit of the
hand-held cellular telephone system when the power level is greater
than a predetermined threshold.
35. The hand-held cellular telephone system of claim 33, wherein
the at least one emergency telephone call is a single button
enhanced 911 call, wherein activation of the single button enables
the reserve power, the enabled reserve power providing power for:
activation of the hand-held cellular telephone system, wherein the
hand-held cellular telephone system comprises telephone circuitry
and GPS receiver circuitry; establishment of a call between the
hand-held cellular telephone system and the emergency operator;
transfer of GPS satellite acquisition aiding information to the
hand-held cellular telephone system; receipt of GPS signals; and
communication of GPS satellite information to the emergency
operator.
36. The hand-held cellular telephone system of claim 35, wherein
the enabled reserve power further provides power for transfer of
GPS satellite acquisition aiding information to the hand-held
cellular telephone system.
37. The hand-held cellular telephone system of claim 35, wherein
the enabled reserve power further provides power for determination
of a position of the portable cellular transceiver.
38. The hand-held cellular telephone system of claim 35, wherein
the GPS satellite information comprises at least one of GPS
pseudorange information, digitized signals from which GPS
pseudorange information can be determined, and latitude and
longitude information.
39. The hand-held cellular telephone system of claim 33, wherein
the at least one emergency telephone call is an emergency 911 call,
wherein activation of the single button enables the reserve power,
the enabled reserve power providing power for: activation of the
hand-held cellular telephone; establishment of a high power call
between the hand-held cellular telephone and at least three
cellular base stations, wherein the at least three cellular base
stations determine the location of the hand-held cellular telephone
using a network overlay approach, wherein the network overlay
allows for a determination of the location using a time of arrival
of the signal at the at least three cellular base stations.
40. The hand-held cellular telephone system of claim 33, wherein
the at least one low power mode selectively powers down circuitry
of the hand-held cellular telephone system, wherein a single button
of the hand-held cellular telephone system provides the at least
one call, wherein activation of the single button results in:
selective application of power to GPS receiver circuitry, wherein a
position information of the hand-held cellular telephone system is
determined; and selective application of power to communication
circuitry, wherein the position information of the hand-held
cellular telephone system is transmitted along with an emergency
message to an emergency operator.
41. A computer readable medium containing executable instructions
which, when executed in a processing system, causes the system to
perform the steps for providing reserve power in a portable
cellular transceiver comprising a Global Positioning System (GPS)
receiver comprising: monitoring a power level of a battery of the
portable cellular transceiver; and automatically placing the
portable cellular transceiver into at least one low power mode when
the power level reaches at least one threshold level, wherein the
at least one threshold level reserves power for at least one
emergency telephone call.
42. The computer readable medium of claim 41, wherein the
processing system is further configured to perform the steps of:
determining if a power level of the battery is greater than a
predetermined threshold; and providing power to at least one
circuit of the portable cellular transceiver when the power level
is greater than a predetermined threshold.
43. The computer readable medium of claim 41, wherein the at least
one emergency telephone call is an enhanced 911 call, wherein the
reserve power allows for: activation of the portable cellular
transceiver; establishment of a call between the portable cellular
transceiver and a cellular base station; transfer of GPS satellite
acquisition aiding information to the portable cellular
transceiver; receipt of GPS signals; and communication of GPS
satellite information to the cellular base station.
44. The computer readable medium of claim 43, wherein the enhanced
911 call is a single button call, wherein one button of the
portable cellular transceiver enables the emergency telephone
call.
45. The computer readable medium of claim 41, wherein the step of
automatically placing the portable cellular transceiver into at
least one low power mode comprises selectively powering down
circuitry of the portable cellular transceiver.
46. The computer readable medium of claim 41, wherein the
processing system is further configured to allow a single button of
the portable cellular transceiver to provide the at least one
emergency telephone call, wherein activation of the single button
results in: selective application of power to GPS receiver
circuitry, wherein a position information of the portable cellular
transceiver is determined; selective application of power to
communication circuitry, wherein the position information of the
portable cellular transceiver is transmitted along with an
emergency message to an emergency operator.
Description
FIELD OF THE INVENTION
[0001] This invention relates to cellular telephones that integrate
Global Positioning System (GPS) receivers. More particularly, this
invention relates to power management in a cellular telephone.
BACKGROUND OF THE INVENTION
[0002] GPS receiver systems are becoming prevalent among consumers
as the GPS system cost decreases and technology allows for the
miniaturization of these systems. The popularity of these systems
is in large part due to their ability to provide highly accurate
position information at a very low cost using a hand-held unit that
is small enough to fit in a briefcase or a purse. As a result of
this popularity, GPS receiver systems are being integrated into
other electronic systems, for example, cellular telephone systems.
In this manner, the GPS portion of the electronic system is able to
simultaneously provide the position of the cellular telephone user
to the user and/or a party that is being communicated with using
the integrated cellular telephone. This type of system is typically
useful to, but not limited to, emergency services personnel that
need to quickly identify the location of a caller, such as an
enhanced 911 system.
[0003] With regard to electronic systems having integrated GPS
systems, emphasis has been placed on the handheld cellular
telephone systems because of their prevalent use in society. With
the cellular telephone, the battery life of the telephone has a
significant impact on the acceptance of a particular model of phone
by consumers. Therefore, as the integration of a GPS receiver into
a cellular telephone device is likely to increase the power
consumption of the telephone device, the telephone designer must
focus particular effort on decreasing the power requirements of the
integrated telephone device so as to increase the operating time of
the device and maximize the availability of the device to a
user.
[0004] One of the main reasons for the acquisition of a cellular
telephone is for use in emergency situations encountered by the
user. However, when the cellular telephone is allowed to be used
until the battery is dead, the cellular telephone becomes
unavailable for emergency use. Prior art cellular telephones fail
to automatically provide the reservation of enough power in a
cellular telephone battery to allow a 911 emergency call to be
placed by the user.
[0005] One prior art technique used to provide reserve battery
power in other types of portable electronic devices, for example,
portable personal computers, is to provide a separate battery for
reserve use only. The problem with the use of a spare battery is
that, while providing enough power to allow the user to perform a
save to the memory before a complete power loss, the battery
increases the size and weight of the portable computer.
[0006] Another prior art power reservation technique used in
portable personal computers is to provide a save-to-disk suspend
mode that prevents data loss when the batteries run out of power by
copying all system data to a disk drive and turning the computer
off. However, prior art cellular telephone systems do not provide
an equivalent feature. Thus, the prior art integrated cellular
telephone lacks the automatic provision of reserve power for use in
placing emergency calls with the cellular telephone.
SUMMARY OF THE INVENTION
[0007] A method and an apparatus for providing reserve power in a
cellular telephone are provided. In one embodiment, reserve power
is provided in a portable cellular transceiver comprising a Global
Positioning System (GPS) receiver by monitoring, continuously or
periodically, a power level of a battery of the portable cellular
transceiver. A determination is made as to whether the power level
of the battery is greater than a predetermined threshold. Based on
the available power level, the portable cellular transceiver is
automatically placed into at least one low power mode when the
power level reaches a corresponding threshold level. The low power
mode may be a shut-off mode which selectively powers down circuitry
of the portable cellular transceiver. The corresponding threshold
level reserves power for an emergency telephone call. Power is
provided to the circuitry of the portable cellular transceiver when
the available power level is greater than the predetermined
threshold. The reserve power provides power for the activation of
the portable cellular transceiver, establishment of a call between
the portable cellular transceiver and a cellular base station,
transfer of GPS satellite acquisition aiding information to the
portable cellular transceiver, receipt of GPS signals, and
communication of GPS satellite information (e.g. pseudoranges or a
position) to the cellular base station, and, optionally,
determination of a position of the portable cellular
transceiver.
[0008] In an embodiment, the emergency telephone call may be an
enhanced 911 call. The emergency telephone call may be a single
button call, wherein activation of a single button of the portable
cellular transceiver causes the selective application of power to
GPS receiver circuitry and selective application of power to
communication circuitry. The emergency message may comprise voice
data, alphanumeric message data, or some combination of voice and
alphanumeric message data.
[0009] In an embodiment, the portable cellular transceiver
comprises a power detection circuit for monitoring a power level of
a battery of the portable cellular transceiver. While the
monitoring may be continuous, it may be on a regular basis, a
scheduled basis, a predetermined basis, or based on the mode of
operation (i.e., stand-by mode or during a phone call).
Furthermore, the portable cellular transceiver comprises a power
control circuit for automatically placing the portable cellular
transceiver into at least one shut-off mode when the power level
reaches at least one threshold level. Moreover, the portable
cellular transceiver comprises a comparator circuit for determining
if a power level of the battery is greater than a predetermined
threshold, wherein the power control circuit provides power to at
least one circuit of the portable cellular transceiver when the
power level is greater than a predetermined threshold.
[0010] These and other features, aspects, and advantages of the
present invention will be apparent from the accompanying drawings
and from the detailed description and appended claims which
follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention is illustrated by way of example and
not limitation in the figures of the accompanying drawings, in
which like references indicate similar elements and in which:
[0012] FIG. 1 is a block diagram of an integrated cellular
telephone of one embodiment.
[0013] FIG. 2 is a flowchart for providing reserve power in a
portable cellular transceiver or telephone of one embodiment.
DETAILED DESCRIPTION
[0014] A method and an apparatus for providing reserve power in a
cellular telephone are provided. In the following description, for
purposes of explanation, numerous specific details are set forth in
order to provide a thorough understanding of the present invention.
It will be evident, however, to one skilled in the art that the
present invention may be practiced without these specific details.
In other instances, well-known structures and devices are shown in
block diagram form in order to avoid unnecessarily obscuring the
present invention. One example of a GPS receiver to be used with
the present invention described herein is found in U.S. Pat. No.
5,663,734 by Norman F. Krasner.
[0015] A method and an apparatus is described herein for providing
reserve power in a portable communication device. The portable
communication device of one embodiment is a cellular telephone,
sometimes also referred to as a cell telephone or personal
communication system (PCS). The portable communication device may
comprise a satellite communication handset, but the embodiment is
not so limited. In one embodiment, reserve power is provided in a
portable cellular transceiver comprising a satellite positioning
system (SPS) receiver by monitoring a power level of a battery of
the portable cellular transceiver using a power detection circuit.
The satellite positioning system receiver may be a Global
Positioning System (GPS) receiver, but the embodiment is not so
limited. A comparator circuit determines whether the power level of
the battery is greater than a predetermined threshold. Based on the
available power level, a power control circuit automatically places
the transceiver into at least one low power mode, or shut-off mode,
when the power level reaches a corresponding threshold level. In
one embodiment, the power control circuit may cause to be displayed
a percentage of power remaining. In one embodiment, the power
control circuit may predict and cause to be displayed a time
remaining until the telephone is placed into a low power mode. In
one embodiment, the power control circuit may predict and cause to
be displayed a time that the telephone will be placed into a low
power mode. The predicted time may be in GPS time, or in Universal
Time Coordinate (UTC) time, but the embodiment is not so
limited.
[0016] The low power mode selectively powers down circuitry of the
portable cellular transceiver. Alternatively, the low power mode
disables selected capabilities of the cellular transceiver based on
a prespecified hierarchy. The corresponding threshold level
reserves power for an emergency telephone call. Power is provided
to the circuitry of the portable cellular transceiver when the
available power level is greater than the predetermined
threshold.
[0017] The reserve power provides power for the activation of the
portable cellular transceiver, establishment of a call between the
portable cellular transceiver and a cellular base station, transfer
of GPS satellite acquisition aiding information to the portable
cellular transceiver, receipt of GPS satellite information,
communication of GPS satellite information to the cellular base
station, and determination of a position of the portable cellular
transceiver.
[0018] Alternatively, the portable cellular transceiver may not
require any GPS satellite acquisition aiding information. The GPS
satellite information may comprise GPS pseudorange information,
digitized signals from which GPS pseudorange information can be
determined, and latitude and longitude information, but the
embodiment is not so limited. The emergency telephone call may be a
single button enhanced 911 call.
[0019] FIG. 1 is a block diagram of an integrated cellular
telephone 100 of one embodiment. The cellular telephone 100
comprises telephone circuitry 102, position circuitry 104, and
power management circuitry 101. The power management circuitry 101
comprises a battery 106, power detection circuitry 108, comparator
circuitry 110, and power control circuitry 112. The battery 106
provides power to circuits of the cellular telephone 100. The power
detection circuitry 108 monitors a power level of the battery 106.
While the monitoring may be continuous, it may be on a regular
basis, a scheduled basis, a predetermined basis, or based on the
mode of operation (i.e., stand-by mode or during a phone call). The
comparator circuitry 110 determines whether a power level of the
battery 106 is greater than a predetermined threshold. In one
embodiment, the comparator circuitry 110 may provide a quantitative
measurement of the power level of the battery 106, but the
embodiment is not so limited. The power control circuitry 112
controls application of power from the battery 106 to the telephone
circuitry 102 and position circuitry 104 based on the available
battery power. In one embodiment, the telephone circuitry 102 and
the position circuitry 104 comprise shared circuitry.
[0020] The power control circuitry 112 automatically places the
portable cellular telephone 100 into at least one low power mode
when the battery power level reaches at least one threshold level.
One or more low power modes may selectively power certain
components of the cellular telephone 100, thereby selectively
enabling functions of the cellular telephone 100, but the
embodiment is not so limited. One low power mode selectively
disables circuitry of the cellular telephone 100, thereby allowing
for a threshold power level that reserves enough power to allow a
user to place at least one emergency telephone call. The low power
mode may disable selected capabilities of the cellular transceiver
based on a prespecified hierarchy, but the embodiment is not so
limited.
[0021] In an alternate embodiment, the power management circuitry
may comprise an auxiliary battery for use in placing emergency
telephone calls. In this alternate embodiment, the power control
circuitry allows the cellular transceiver to be used until the main
battery is drained. At such time as an emergency call is activated,
the power control circuit provides power to the telephone circuitry
and the position circuitry from the separate battery.
[0022] In one embodiment, the emergency telephone call may comprise
a call to a 911 operator, but the embodiment is not so limited. In
placing the emergency telephone call, the power control circuitry
112 provides power to the telephone circuitry 102 and the position
circuitry 104 of the portable cellular telephone 100 when the power
level is greater than a predetermined threshold. In one embodiment,
the position circuitry 104 comprises a GPS receiver, but the
embodiment is not so limited. In one embodiment, the position
circuitry 104 determines the actual position of the cellular
telephone 100, in latitude and longitude, and the telephone
circuitry 102 transmits the position along with an emergency
message to an emergency operator. In an alternate embodiment, the
position circuitry 104 determines pseudoranges of the cellular
telephone 100, and the telephone circuitry 102 transmits the
pseudoranges along with an emergency message to a cellular base
station or an emergency operator. In another alternate embodiment,
the position circuitry 104 provides digitized signals from which
pseudoranges of the cellular telephone 100 can be determined, and
the telephone circuitry 102 transmits the digitized signals along
with an emergency message to a cellular base station or an
emergency operator. The use of position overlay information may be
incorporated in which the position circuitry 104 uses information
overlaid with the communication signals to determine the position
of the cellular telephone 100. The overlay information may comprise
the pseudorange, time of arrival, or other timing information
derived from the communication signals.
[0023] In yet another embodiment, the power control circuitry 112
only provides power to the telephone circuitry 102 to allow the
emergency telephone call to be placed. In this embodiment, the
reserve power allows for activation of the portable cellular
telephone. A high power call is established between the portable
cellular telephone and at least three cellular base stations. The
three cellular base stations determine the location of the portable
cellular telephone using a network overlay approach. The network
overlay approach provides for a determination of the location of
the portable cellular telephone using a time of arrival of the
signal at the at least three cellular base stations, but the
embodiment is not so limited.
[0024] In one embodiment, a single button of the portable cellular
telephone 100 may provide the emergency telephone call. Activation
of the single button results in selective application of power to
the telephone circuitry 102 and the position circuitry 104. In one
embodiment, the position circuitry 104 determines a position of the
portable cellular telephone 100. In an alternate embodiment, the
position circuitry 104 provides signals from which the position of
the portable cellular telephone 100 can be determined. The
telephone, or communication, circuitry 102 transmits a position of
the portable cellular telephone 100 along with an emergency message
to an emergency operator. The emergency message may comprise
identification and position of a user, but the embodiment is not so
limited.
[0025] While a user may make an emergency call with the cellular
telephone by dialing the sequence "9"-"1"-"1", the emergency
telephone call of one embodiment may be a single button enhanced
911 call, but the embodiment is not so limited. The enhanced 911
call activates a minimum sub-set of circuitry in the cellular
telephone that is used to make an emergency call. When using the
enhanced 911 call, the activation of a single button enables the
reserve power, and the enabled reserve power provides power for
activation of the telephone circuitry 102 and the position
circuitry 104 of the cellular telephone 100. The single emergency
button may be activated in the middle of an existing telephone
call, in which case the telephone circuitry 102 and the position
circuitry 104 may already be provided with power.
[0026] Upon activation of the single emergency button, a call is
established between the portable cellular telephone 100 and a
cellular base station. Global Positioning System satellite
acquisition aiding information may be transferred to the portable
cellular telephone 100. The GPS satellite information is received
at the cellular telephone, and the GPS satellite information is
communicated to the cellular base station. In one embodiment,
positioning information can also be derived from communication
signals using a cellular telephone overlay approach. Other
alternative location determining systems (e.g. Loran) may also be
used, and the mobile unit may determine its own position or may be
assisted by a location assistance system such as a location server.
In one embodiment, a position of the portable cellular telephone
100 is determined using circuitry of the cellular base station. In
one embodiment, a position of the portable cellular telephone 100
may be determined using circuitry of the cellular telephone 100,
wherein the position is communicated to the cellular base station
along with an emergency message, but the embodiment is not so
limited.
[0027] FIG. 2 is a flowchart for providing reserve power in a
portable cellular transceiver or telephone of one embodiment. In
one embodiment, the cellular telephone comprises a GPS receiver,
but the embodiment is not so limited. In one embodiment, the
cellular telephone comprises circuitry for determining a position
of the cellular telephone, but the embodiment is not so limited.
Operation begins at step 202, at which power is activated to the
cellular telephone. Upon activation of power to the cellular
telephone monitoring of the power level of the battery commences.
The power level of the cellular telephone battery is monitored and,
at step 204, the power level of the battery is determined. At step
206, a determination is made as to whether the power level of the
battery is greater than a predetermined threshold. If the battery
power level is greater than a predetermined threshold, battery
power is provided to the components of the cellular telephone, at
step 208.
[0028] The determination as to whether the battery power level is
greater than a predetermined threshold may comprise a quantitative
determination of the battery power level. The quantity measured may
comprise maximum voltage level, change in voltage, and a
combination of maximum voltage and change in voltage, but the
embodiment is not so limited. The quantified battery power level
may be used in a determination as to what particular circuitry or
what particular functions of the cellular telephone are to be
activated, but the embodiment is not so limited. Following the
provision of power to the component circuitry of the cellular
telephone, at step 208, operation continues by repeating steps 204,
206, and 208, wherein the power level of the battery is monitored
while the cellular telephone is turned on.
[0029] If the battery power level is determined to be less than a
predetermined threshold, at step 206, the cellular telephone, at
step 210, is placed in a low power mode. In one embodiment, there
may be more than one low power mode, but the embodiment is not so
limited. For example, a low power mode may provide a first
threshold level that provides enough power to send and receive
calls having a limited duration. Another low power mode may provide
a second threshold level that provides only enough power to
initiate a call by selectively activating specific circuitry in the
cellular telephone. Another low power mode may provide a third
threshold level that provides only enough power to receive a call
by selectively activating specific circuitry in the cellular
telephone. Another low power mode may provide a fourth threshold
level that reserves power for at least one emergency telephone
call. This low power mode selectively powers down circuitry of the
cellular telephone, thereby providing an improvement in the
cellular telephone design that results in increased availability of
the cellular telephone in response to emergency situations.
[0030] In one embodiment, the emergency telephone call is an
enhanced 911 call. For the enhanced 911 call, the reserve power
allocated allows for activation of the cellular telephone. In one
embodiment, the activation comprises enablement of the circuitry
necessary to determine the position of the cellular telephone and
to complete an emergency call, but the embodiment is not so
limited. Upon activation, a call is established between the
cellular telephone and a cellular base station. When the call is
established, GPS satellite acquisition aiding information may be
transferred to the cellular telephone. After receipt of the GPS
satellite acquisition information, GPS satellite information is
communicated to the cellular base station. The GPS satellite
information is used to determine a position of the cellular
telephone, but the embodiment is not so limited. In one embodiment,
the GPS satellite information comprises the position of the
cellular telephone.
[0031] In one embodiment, the emergency telephone call is a single
button call, wherein one button of the cellular telephone enables
the emergency telephone call. When a single button of the cellular
telephone provides the at least one emergency telephone call, the
activation of the single button results in selective application of
power to the GPS receiver circuitry of the cellular telephone. The
GPS receiver circuitry determines a position information of the
cellular telephone. Moreover, activation of the single button
results in selective application of power to telephone or
communication circuitry. The telephone circuitry transmits the
position information of the cellular telephone along with an
emergency message to an emergency operator. In one embodiment, the
emergency message comprises voice data. In an alternate embodiment,
the emergency message comprises an alphanumeric message, the
alphanumeric message comprising the identification and location
information of the user. In another alternate embodiment, the
emergency message comprises voice data and alphanumeric data, where
the alphanumeric data comprises position information of the
user.
[0032] Thus, a method and an apparatus for providing reserve power
in a cellular telephone have been provided. Although the present
invention has been described with reference to specific exemplary
embodiments, it will be evident that various modifications and
changes may be made to these embodiments without departing from the
broader spirit and scope of the invention as set forth in the
claims. Although the methods and apparatus of the present invention
have been described with reference to GPS satellites and GPS
signals, it will be appreciated that the teachings are equally
applicable to positioning systems which utilize pseudolites or a
combination of satellites and pseudolites. Pseudolites are ground
based transmitters which broadcast a PN code (similar to a GPS
signal) modulated on an L-band or other carrier signal, generally
synchronized with GPS time. Each transmitter may be assigned a
unique PN code so as to permit identification by a remote receiver.
Pseudolites are useful in situations where GPS signals from an
orbiting satellite might be unavailable, such as tunnels, mines,
buildings or other enclosed areas. The term "satellite", as used
herein, is intended to include pseudolite or equivalents of
pseudolites, and the term GPS signals, as used herein, is intended
to include GPS-like signals from pseudolites or equivalents of
pseudolites.
[0033] In the preceding discussion the invention has been described
with reference to application upon the United States Global
Positioning Satellite (GPS) system. It should be evident, however,
that these methods are equally applicable to similar satellite
positioning systems, and in particular, the Russian Glonass system.
The term "GPS" used herein includes such alternative satellite
positioning systems, including the Russian Glonass system.
Accordingly, the specification and drawings are to be regarded in
an illustrative rather than a restrictive sense.
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