U.S. patent number 7,257,374 [Application Number 11/008,759] was granted by the patent office on 2007-08-14 for automatic security locking method and system for wireless-enabled devices.
This patent grant is currently assigned to Cingular Wireless II, LLC. Invention is credited to George Samuel Creigh.
United States Patent |
7,257,374 |
Creigh |
August 14, 2007 |
Automatic security locking method and system for wireless-enabled
devices
Abstract
A security system for wireless devices such as mobile phones
includes a wireless signal transmitter, and a signal strength
detector and microprocessor associated with the wireless device
being safeguarded. The microprocessor disables or locks the
wireless device if the measurement by the detector of the strength
of the signal transmitted by the wireless transmitter is less than
a predetermined value, thereby indicating that there is more than a
predetermined separation distance between the protected device and
the transmitter, i.e., that, e.g., someone has taken the device.
The disabled wireless device stays disabled until the measured
signal strength is again greater than the predetermined value. Once
this value is reached the device is automatically unlocked or
enabled.
Inventors: |
Creigh; George Samuel (Acworth,
GA) |
Assignee: |
Cingular Wireless II, LLC
(Atlanta, GA)
|
Family
ID: |
38337094 |
Appl.
No.: |
11/008,759 |
Filed: |
December 10, 2004 |
Current U.S.
Class: |
455/41.2;
455/411 |
Current CPC
Class: |
H04B
17/318 (20150115); H04L 63/107 (20130101); H04M
1/66 (20130101); H04W 12/08 (20130101); H04L
63/10 (20130101); H04M 1/67 (20130101); H04W
8/245 (20130101); H04B 17/382 (20150115); H04M
2250/02 (20130101); H04W 48/04 (20130101); H04M
1/72412 (20210101) |
Current International
Class: |
H04B
7/00 (20060101); H04M 1/66 (20060101) |
Field of
Search: |
;370/310
;455/456.4,410,425,41.1-41.3 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Sobutka; Philip J.
Attorney, Agent or Firm: Gardner Groff Greenwald &
Villanueva, P.C.
Claims
What is claimed is:
1. A method for selectively disabling a wireless-enabled device,
said method comprising: transmitting a short range wireless signal
using one of (i) said wireless-enabled device and (ii) a second
device separate from the wireless-enabled device; receiving a
predetermined threshold value from the user of the wireless-enabled
device; measuring, using the other of the second device and the
wireless-enabled device, signal strength of the signal;
automatically disabling at least one function of the
wireless-enabled device when the signal strength is less than the
predetermined threshold value; and automatically reenabling the at
least one function of the wireless-enabled device when the signal
strength is equal to or greater than the predetermined threshold
value.
2. A method according to claim 1 wherein said disabling of the at
least one function comprises locking the wireless-enabled device so
as to prevent use thereof.
3. A method according to claim 1 wherein the signal strength is
measured periodically.
4. A method according to claim 1 wherein the wireless-enabled
device comprises a wireless handset and disabling of the at least
one function comprises locking the handset against making outgoing
calls.
5. A method according to claim 4 wherein said disabling of at least
one function further comprises locking the handset against
receiving incoming calls.
6. A method according to claim 1 wherein the method further
comprises providing a bypass option for bypassing the disabling
step.
7. A method according to claim 6 wherein a password is received by
the wireless-enabled device prior to executing the bypass
option.
8. A method according to claim 6 further comprising deactivating
the bypass option after a predetermined time period.
9. A security system, comprising: a portable transmitter, adapted
to be carried or worn on the person of a user of the system, for
transmitting a short range wireless signal; and a portable
wireless-enabled device including a user interface for receiving a
threshold value from the user, wherein the portable wireless-enable
device measures the signal strength of the short range wireless
signal, and disables at least one function of the wireless-enabled
device when the measured signal strength is less than the
predetermined threshold value.
10. A system according to claim 9 wherein said transmitter is
contained in a device comprising one of a set of earphones, a
writing instrument, eyeglasses and a wristwatch.
11. A system according to claim 9 wherein said wireless-enabled
device measures the signal strength of said signal
periodically.
12. A system according to claim 9 wherein the portable
wireless-enabled device comprises a wireless handset and wherein
the at least one disabled function includes the function for making
outgoing calls.
13. A system according to claim 12 wherein the at least one
disabled function includes the function for receiving incoming
calls.
14. A system according to claim 9 wherein the wireless-enabled
device is operable to bypass the automatic disabling of the at
least one function.
15. A system according to claim 14 wherein the bypass option is
executed upon receipt of a valid password.
16. A system according to claim 14 wherein the bypass option is
deactivated after a predetermined time period.
17. A method for selectively locking a Bluetooth-enabled wireless
handset, said method comprising: transmitting a Bluetooth signal
using a transmitter separate from the handset; receiving a
user-designated threshold value representing a maximum distance
that the transmitter can be separated from the Bluetooth-enabled
wireless handset; monitoring said signal using the wireless
handset; automatically locking the wireless handset to prevent use
of the handset when a determination is made that the strength of
the monitored signal is less than the user-designated threshold
value; and automatically unlocking the wireless handset when the
signal strength is equal to or greater than the user-designated
threshold value.
18. A method according to claim 17 wherein said transmitter is
incorporated in a device that is wearable on the person of a user
or a device capable of being carried on the person of a user.
19. A method according to claim 17 wherein said transmitter is
incorporated in a device comprising one of a set of earphones, a
writing instrument, eyeglasses and a wristwatch.
20. A method according to claim 17 wherein locking the handset
prevents both incoming and outgoing calls.
21. A method according to claim 17 wherein the method further
comprises providing a bypass option for bypassing the locking
step.
22. A method according to claim 21 wherein the bypass option is
executed upon receipt of a valid password.
23. A method according to claim 21 wherein the bypass option is
deactivated after a predetermined time period.
Description
FIELD OF THE INVENTION
The present invention generally relates to wireless terminal
devices such as wireless handsets and more particularly, to
security systems and methods for automatically disabling or locking
such devices.
BACKGROUND OF THE INVENTION
Wireless devices such as laptop computers, palm-sized computing
devices, two-way pagers, cellular phones and personal digital
assistant (PDA) devices have become increasingly popular. Some of
these devices enable the user to communicate with others vocally
and through electronic mail and instant messaging, as well as to
collect, analyze and distribute important information as the user
travels. An important trend involves making the devices as small
and compact as possible. While these advantages have been warmly
embraced by the public, one disadvantage of the compactness,
usefulness, easy accessibility and ubiquity of these devices is
that the devices have now become increasingly vulnerable to theft
or other unauthorized use.
Many computers, especially portable computers have been secured
from unauthorized use through different preventive techniques. One
previous method of preventing unauthorized use is an automatic
logging off system. This system automatically logs off the computer
if the computer device has been inactive for a specified period of
time much like a computer screensaver. If an authorized user has
logged onto a secure computer, but not entered any input for a
predetermined period of time, the concern is that the authorized
user might have discontinued use and left the computer unattended
without securing the computer. Under these circumstances, if an
unauthorized user can get to the computer during this time while
the computer is still logged on, the unauthorized person will have
full access to the information and resources on the computer. The
likelihood of this occurring can be diminished by having the
computer automatically log off if the computer goes unused for a
specified period of time. With this approach, in order to obtain
access again, the authorized user must log back onto the system by
entering his or her password.
While the automatic timed lock approach is useful because it
protects information and resources, it may also be an inconvenience
to authorized users. In this regard, the authorized user is
inconvenienced, and productivity is impaired, when the user has to
log back in to the computer each time he or she has to leave the
computer for a short period of time. Logging back on can become an
annoyance if the process needs to be repeated in a nearly
continuous manner in situations where the user is frequently away
from the computer. A longer period of time for automatic log off
can be provided but this undermines the effectiveness of the whole
auto log off approach
Another preventative measure taken to secure information on
computers is the use of a magnetic swipe card to unlock a computer
once the computer has timed out. The computer time out mechanism
works the same as the method described above, i.e., log off is
automatic if the computer is not used for a specified period of
time but instead of entering a password to regain access, a card is
swiped through a reader which is associated with the computer. For
example, such a reader may be attached to the computer by a daisy
chain. This swiping of the card unlocks the computer.
Although the use of such a swipe card allows the user to unlock the
computer without having to enter a password, the repetitive action
of having to swipe the card through the reader each time the
computer locks as a result of the user stepping away from his desk
can still become annoying. Further, with the new generation of
compact, mobile computer devices, the card reader itself may also
be larger than the device being protected, thus defeating the
convenience of having a mobile device. Also, the card may be left
at the desk unintentionally, as swipe cards often are, thereby
defeating the security provided by use of such a card.
A further type of security system that is of particular interest
here is wireless locking systems that use a wireless signaling
device to cause locking of another wireless-enabled device. For
example, such systems are used to remotely control door locks for
automotive vehicles, and in a number of other applications.
Patent publications of interest here include U.S. Patent
Application Publication No. 2004/0178907A1 which relates to an
alarm system for preventing loss or theft of a portable and/or
movable device such as a mobile telephone. The system determines
the distance between the telephone and another movable and/or
portable device using the Global Positioning System (GPS) and an
alarm is generated when that distance exceeds a predetermined
distance. At least one of the devices may be locked when the alarm
is triggered. Other patent publications of background interest
include Publication Nos. U.S. 2004/0215816A1 and U.S.
2003/0184431A1.
U.S. Pat. No. 5,635,857 discloses a mobile phone alarm system
including a phone device attached to the mobile phone and body
device adapted to be carried by a user. The phone device repeatedly
transmits a verification signal of limited power to the body
device. The signal is only identifiable within a predetermined
limited distance and if the separation distance between the devices
exceeds this predetermined distance, the body device receives no
signal and alarms.
SUMMARY OF THE INVENTION
In accordance with one aspect thereof, the present invention
provides improved protection against theft, and other unauthorized
use, for portable wireless-enabled devices, such as cellular
telephones, which are capable of receiving short range wireless
signals.
In accordance with one embodiment of the invention, there is
provided a method for selectively disabling a wireless-enabled
device, the method comprising:
generating a short range wireless signal using one of (i) the
wireless-enabled device and (ii) a further device separate from the
wireless-enabled device;
measuring, using the other of the further device and the
wireless-enabled device, a parameter associated with the short
range signal which is related to the separation distance between
the wireless-enabled device and the further device; and
automatically disabling at least one function of the
wireless-enabled device when the measured parameter is of value
outside of a predetermined value and thus the separation distance
is outside of a preselected threshold.
Preferably, the parameter measured comprises signal strength and
the at least one function is disabled when the measured signal
strength is less than a predetermined value.
The disabling of the at least one function preferably comprises
locking the wireless-enabled device so as to prevent use
thereof.
In one important implementation, the wireless-enabled device
comprises a wireless handset and disabling of the at least one
function comprises locking the handset against making outgoing
calls. In one embodiment of this aspect of the invention, the
disabling of at least one function further comprises locking of the
handset against receiving incoming calls.
In accordance with another important feature, the method further
comprises providing a bypass option for bypassing the at least one
function such that, when said bypass option is exercised, a bypass
is executed wherein the at least one function is not disabled even
though said measured parameter is of a value outside of said
predetermined value. Preferably, before the bypass option can be
exercised, a password must be provided. Advantageously, the bypass,
when executed, is turned off after a predetermined time period so
that, after the time period has run out, the at least one function
can again be disabled depending on the value of the measured
parameter.
Preferably, the measured parameter is measured periodically.
In another preferred implementation, the parameter is signal
strength, and one of a plurality of different signal strengths can
be selected by the user based on selection of one of a plurality of
corresponding separation distances between the wireless-enabled
device and the further device.
Preferably, after the at least one function is disabled, said
parameter is again measured, and said disabling of the at least one
function is terminated when the measured parameter is of a value
within said predetermined value.
In accordance with another embodiment of the invention, a security
system for a portable wireless-enabled device, said system
including:
a portable transmitter, adapted to be carried or worn on the person
of a user of the system, for generating a short range wireless
signal; and
the portable wireless-enabled device including means for measuring
the signal strength of said signal so as to provide an indication
of the separation distance between the transmitter and the device,
and means for disabling at least one function of the
wireless-enabled device when the measured signal strength is less
than a predetermined value, thereby indicating that the separation
distance is more than a predetermined threshold distance.
Advantageously, the transmitter is contained in a device comprising
one of a set of earphones, a writing instrument, eyeglasses and a
wristwatch.
In an important implementation, the portable wireless-enabled
device comprises a wireless handset and the means for disabling the
at least one function comprises means for locking the handset
against making outgoing calls. Advantageously, the means for
disabling at least one function comprises means for also locking of
the handset against receiving incoming calls.
Preferably, the wireless-enabled device includes a processor for
providing a bypass option for bypassing the automatic disabling of
the at least one function such that, when the bypass option is
exercised, a bypass is executed wherein the at least one function
is not disabled even though the measured signal strength is of a
value less than the predetermined value. Advantageously, before the
bypass option can be exercised, the processor requires that a
password be provided. Preferably, the processor, when the bypass is
executed, turns off the bypass after a predetermined time period so
that the at least one function can again be disabled depending on
the measured signal strength.
Advantageously, the wireless-enabled device measures the signal
strength of the signal periodically.
Preferably, the wireless-enabled device provides for selection of
one of a plurality of different signal strengths by the user based
on selection of one of a plurality of corresponding separation
distances between the wireless-enabled device and the
transmitter.
Preferably, after the at least one function is disabled, the
wireless-enabled device again measures signal strength and the
disabling of the at least one function is terminated when the
measured signal strength is greater than said predetermined
value.
In accordance with yet another embodiment of the invention, there
is provided a method for selectively locking a Bluetooth-enabled
wireless handset, the method comprising:
generating a Bluetooth signal using a transmitter separate from the
handset;
monitoring the signal using the wireless handset so as to determine
when the signal is of a strength less than a selected level and
thus that the handset is more than a predetermined separation
distance from the transmitter; and
automatically locking the wireless handset so as to prevent at
least outgoing calls from being made therefrom when a determination
is made that the strength of the monitoring signal is less than the
selected level.
In one implementation, the transmitter is contained in a device
that is wearable on the person of a user or in a device capable of
being carried on the person of a user.
Advantageously, the transmitter is contained in a device comprising
one of a set of earphones, a writing instrument, eyeglasses and a
wristwatch.
In one advantageous implementation, locking of the handset prevents
both incoming and outgoing calls.
In accordance with an important feature of this aspect of the
invention, the method further comprises providing a bypass option
for bypassing the automatic locking of the handset such that, when
the bypass option is exercised, a bypass is executed wherein
locking of the handset does not take place even though the measured
signal strength is less than the selected value. Preferably, before
the bypass option is exercised, a password is required.
Advantageously, the bypass, when executed, is turned off after a
predetermined time period so that the locking of the handset can
again occur depending on the value of the measured signal
strength.
Preferably, one of a plurality of different signal strengths can be
selected by the user based on selection of one of a plurality of
corresponding separation distances between the wireless handset and
the transmitter.
Preferably, after the locking occurs, signal strength is again
measured, and the locking is terminated when the measured signal
strength is more than the selected value.
Further features and advantages of the present invention will be
set forth in, or apparent from, the detailed description of
preferred embodiments thereof which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram of one preferred embodiment of
the basic components of the security system of the invention;
and
FIG. 2 is a flow chart of one preferred embodiment of the method of
the invention.
DETAILED DESCRIPTION OF THE PRESENT EMBODIMENT
Generally speaking, the method and system described are directed to
a wireless security system. As required, specific embodiments of
the present invention are disclosed below. It is to be understood
that the disclosed embodiments are merely exemplary of the
invention and that the invention may be embodied in various other
alternative forms.
Referring to FIG. 1, the exemplary embodiments discussed below are
directed to sending a signal from a transmission device 10
containing a wireless transmitter 8 to a wireless-enabled device 12
including a signal detector (or receiver) 14 including a
microprocessor 16 that controls various functions including
automatically disabling the device 12 when the signal detector 14
and thus the device 12, are separated from the transmitter 8 of
device 10 more than a predetermined distance. It is important to
note that, in an alternative embodiment, the signal detector may be
located in a receiver device corresponding to device 10 and the
transmitter 8 may be located in a wireless-enabled device
corresponding to device 12.
The abovementioned separation may occur when, for example, the
wireless-enabled device 12 is stolen or is otherwise transported
away by an unauthorized person. Such separation may also occur, for
example, when the authorized user (having transmitter 8) walks away
from her laptop (having a signal detector 14) that is secured to a
fixed location, such as where the authorized user walks away from a
laptop locked to his or her desk at work (or in a library) to go to
the restroom. In this situation, the authorized user may have the
transmitter 8 attached to his or her person and the receiver or
signal detector 14 may be located in the laptop. In this
implementation, a processor in the laptop (corresponding to
processor 16 of FIG. 1) causes locking up of the laptop to prevent
use when the user carrying transmitter 8 has traveled a
predetermined distance from the detector 14 when, for the example
above, going to the restroom. When the authorized user returns to a
location within the predetermined distance, the signal detector 14
receives a signal that causes the processor in the laptop to
automatically unlock the laptop for use. As discussed below, in a
preferred embodiment, this separation distance or separation range
is determined by measuring the strength of the transmitted signal
using the wireless-enabled device 12.
As indicated above, in the exemplary embodiment illustrated in FIG.
1, the transmitter 8 is located in transmission device 10 and the
signal detector 14 is located in the wireless-enabled device 12
that is to be protected against unauthorized use. In a specific
preferred embodiment, the protected wireless-enabled device 12 may
be a wireless handset, a mobile phone, a PDA, a facsimile, a
copier, and the like. The wireless-enabled device 12 includes the
signal detector 14 that measures the strength of a signal
transmitted from the wireless transmitter 8 so as to determine
whether a security lock on the wireless-enabled device 12 should be
enabled or the wireless-enabled device 12 should be otherwise
disabled. If the signal detector 14 in the wireless-enabled device
12 receives a signal from the transmission device 10 that is below
a predetermined signal strength, the wireless-enabled device 12
will begin its locking process.
The transmitted signal communicated between the transmitter device
8 and the signal detector 12 can take a number of forms. In a
preferred embodiment, the transmitted signal is a short range
wireless signal such as a Wi-Fi or, preferably, a Bluetooth signal.
However, in other embodiments, the transmitted signal could be of a
different wavelength such as an infrared signal. A Bluetooth signal
is generally preferred because its range is consistent with the
separation distances contemplated. In this regard, as discussed
below, the typical maximum operating range for a Bluetooth
operation is about thirty feet although it may be as much as fifty
feet or more or twenty feet or less, depending on the operating
environment. Bluetooth communications and data transfer are
familiar to those skilled in the art, particularly in view of
standards and profile specifications promulgated by the Bluetooth
SIG and other industry entities. The Bluetooth communication
between the signal detector 14 and the transmitter 8 may be of any
now known, or later developed, power rating class associated with
various Bluetooth transmission ranges.
According to the systems and methods of this invention, no physical
connection is required between the transmitter device 10 and the
wireless-enabled device 12. In one exemplary embodiment using
Bluetooth transmission, a one-time Bluetooth "pairing" process is
performed prior to communication between the transmitter 8 and the
signal detector 14 in the wireless-enabled device 12 so that the
devices 8 and 14 can be authorized to communicate with each other
via a "paired link" during a Bluetooth communication session.
Furthermore, the transmitter 8 in the transmission device 10 may
transmit signals for enablement of various devices, including
wireless devices, stand-alone devices, hardwired devices, and the
like. It is an aspect of the invention that such a device or
devices are to be wirelessly enabled and disabled with respect to
various functions thereof as a result of the communication between
the signal detector 14 and the transmitter 8.
In one embodiment, the signal detector 14 in the wireless-enabled
device 12 and the transmitter 8 in the transmission device 10 may
be configured to operate via Bluetooth wireless technology within a
personal-area-network, or piconet. The piconet is composed of a
master and from at least one to numerous active slave devices. Once
the piconet is established, a virtual connection is made and the
participating devices randomly hop frequencies in unison so that
they stay in touch with one another and avoid other piconets that
may be operating in the same room, such as a piconet formed between
a television and its remote control. The device designated as the
master makes the determination of the channel (frequency-hopping
sequence) and phase (timing offset, i.e., when to transmit) that
shall be used by all devices on the piconet. In accordance with
systems and methods of this invention, the master and slave
relationship may be implemented, and/or exchanged, between the
wireless-enabled device 12 and the transmission device 10 carried
by the authorized user.
In implementing this configuration of the invention in connection
with the exemplary embodiment in FIG. 1, the transmission device 10
(including the transmitter 8) operates as the master, and the
wireless-enabled device 12 (including the signal detector 14) is
implemented as the slave. In accordance with standard Bluetooth
link control manager protocol, the transmitter 8 broadcasts a
beacon signal in order to detect the presence of the
wireless-enabled device 12. In a "sniff" mode, the signal detector
14 in the wireless-enabled device 12 detects the broadcast beacon
signal and verifies whether the beacon broadcasted signal is valid.
That is, the signal detector 14 determines whether an address
associated with the broadcast beacon signal transmitted from the
transmission device 10 matches, or is paired with, an address
associated with the transmission device 10. When the address from
each of the devices is authenticated (i.e., a paired link
connection is formed) attachment between the two devices occurs and
communication may freely take place. The broadcast and sniffing
operation between the transmitter 8 and the signal detector 14 may
be continuously or intermittently performed.
Transmission device 10 can also be incorporated in, or form part
of, a number of different devices. For example, the transmission
device 10 and, in particular the transmitter 8, may be incorporated
in a pair of headphones, a writing instrument such as a pen, a
wristwatch, sunglasses, an item of apparel, an item that would be
suspended from a keychain, or the like. In general, anything that
can be carried on the person, or worn, would be a potential
candidate.
Considering the wireless-enabled device 12 in more detail, and
focusing on an implementation wherein wireless-enabled device 12 is
a mobile phone, most mobile phones have a lock function that the
user can enable. For example, some mobile phones allow the user to
lock the keypad upon the entering of a lock code. In a preferred
embodiment, wherein the wireless-enabled device 12 is a mobile
phone, the phone includes a signal detector corresponding to
detector 14 that enables varying signal strengths to be measured.
Such a feature is standard for mobile phones but a conventional
mobile phone may have to be modified to measure the signal
strengths of, e.g., Bluetooth signals.
The control device or microprocessor 16 of device 12 allows the
user, by way of a menu 18 on a display screen 20 on the
wireless-enabled device 12, to set a separation distance range
and/or a signal strength level corresponding to the desired
separation range. The separation distance or range and/or a signal
strength level may be selected by the user and/or by the
microprocessor 16 in response to various conditions, including
presence and location information. Preferably, the presentation
provided by menu 18 would be in terms of different separation
distances. For example, if the wireless-enabled device 12 is to be
locked when the separation distance between transmitter 8 and the
signal detector 14 is greater than thirty feet (which, as indicated
above, is the transmission range of some Bluetooth transmitters)
setting the range at thirty fee will set the signal strength
threshold accordingly.
The control device or microprocessor 16 also controls operation of
a locking function or security lock 22 and, in particular, causes
the wireless-enabled device 12 (e.g., a handset or phone) to lock
in response to the detection of a signal strength level below the
preset threshold and/or if the separation distance or range is
above a predetermined value. The lock function can be set to full
or partial status. Setting the lock 22 to full status results in
the wireless-enabled device (phone) 12 not being able to receive
incoming calls, as well as prevents a user from making outgoing
phone calls with the wireless-enabled device (phone) 12. On the
other hand, by setting the lock parameter to partial, only the
outgoing call function is disabled.
In one preferred embodiment, the range parameter, i.e., the
separation distance between devices 10 and 14, can be set to low,
medium or high. These settings determine how close the transmitter
8 has to be relative to the signal detector 14 to disable or enable
the security lock 22. It will be appreciated that a high range
setting allows the user of the wireless-enabled device 12, when
carrying the transmitting device 10, more freedom to venture away
from the phone 12, i.e., permits a greater separation distance
between transmitter 10 and wireless-enabled device 12, without the
security lock 22 of the wireless-enabled device 12 being activated.
On the other hand, a low setting more severely limits this
separation.
Referring now to FIG. 2, there is shown a flow chart of one
preferred embodiment of the method of the present invention. Once
the lock and range parameters have been set as described above, the
mobile phone begins receiving the transmitted signal, as indicated
by START block 100. Upon the receiving of the signal, a
determination is made as to whether the signal strength of the
received signal is greater than a predetermined value X, as
illustrated by decision diamond 102, wherein the value X is
determined by the range setting. As indicated above, for Bluetooth
operations, X may typically be between about 20 feet and 50
feet.
If the signal strength is greater than X, i.e., the decision is
"Yes," a timer is activated as shown by block 104, so as to provide
a delay before initiating receiving and measuring of the
transmitted signal again.
If the signal strength is, however, below X, then a screen prompt
for the user will appear on the screen of the mobile phone asking
if the automatic locking feature should be disabled, as illustrated
by decision diamond 108. This feature is optional and is provided
so as to permit the authorized user to prevent automatic locking if
circumstances dictate this, i.e., where a co-worker or friend is
given the phone to use or to show someone else in a different part
of the building. The disadvantage of this feature is that a
sophisticated thief may use this feature to disable the locking
function, without the further safeguard discussed below in
connection with decision diamond 118.
If the user fails to choose to disable the automatic locking
function, i.e., the decision is "No," or if an appropriate response
is not entered within a set period of time, then the lock command,
whether partial or full, is sent and the mobile phone enters a lock
mode, as shown by block 110.
After the phone enters the lock mode, a scanning algorithm is
continuously performed, which monitors the strength of the
transmitted signal, shown in block 112. This action is used to
determine whether the separation distance between the signal
detector 14 in the wireless-enabled device 12 and the transmitting
device carried by the authorized user is still greater than the
desired threshold. In other words, if the strength of the signal is
determined to be less than X, i.e., the decision is "No," this
means that the phone is still too far out of range. Under these
circumstances, the scanning operation continues in search of an
acceptable signal strength. On the other hand, once the signal
strength is determined to be greater than X, i.e., the decision is
"Yes," the phone unlocks, as illustrated by block 114. The purpose
of this feature is to provide automatic unlocking when, e.g., the
signal detector 14 in the wireless-enabled device 12 is returned by
an authorized user or is otherwise brought into range of the
transmission device 10.
At this point, the initial measuring strength of the transmitted
signal then begins all over again, as shown by the arrow leaving
block 114 and entering decision diamond 102.
Returning to decision diamond 108, if the user decides to turn the
automatic lock off, i.e., the decision is "Yes," a screen prompt
then appears asking the user to enter his or her password, as shown
in decision diamond 118. If the incorrect password or no password
is entered by the user, the lock command is then sent, as
illustrated through block 110. This feature is a safety measure, or
safeguard, in a case where an unauthorized user is in possession of
the phone. Once the phone is locked, the scanning algorithm
discussed earlier is initiated, as shown in block 112. As discussed
above, the phone would then continuously scan, and measure the
transmitted signal strength until a signal of the minimum strength
is detected which would then cause the phone to unlock, as shown in
block 114. Again, the entire process would then start all over
again, as shown by the arrow leaving block 114 and entering block
102.
Referring again to block 118, if the password entered by the user
is correct, the automatic lock would is then disabled, as shown by
block 120. This disabling of the automatic lock is preferably
limited to a preset period of time, as indicated by timer 122.
After the preset time elapses, the lock will be enabled either by
the user, or automatically, as shown by block 124. Measuring of the
strength of the transmitted signal then begins again, as
illustrated by the arrow leaving block 124 and entering decision
diamond 102.
It is noted that, in embodiments wherein a password is needed to
disable the automatic lock, the password can be entered
automatically, during a predetermined period or periods of the day,
when, for example, the user expects to be frequently in and out of
his or her office without taking the protected wireless-enabled
device 12 or otherwise frequently separated from the
wireless-enabled device 12.
Again, although the invention has been described above in relation
to preferred embodiments thereof, it will be understood by those
skilled in the art that variations and modifications can be
effected in these preferred embodiments without departing from the
scope and spirit of the invention.
* * * * *