Note: Descriptions are shown in the official language in which they were submitted.
CA 02386388 2002-03-27
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FACILITY AND METHOD FOR TRACKING PHYSICAL ASSETS
Reference to Related Application
This is a non-provisional application based on provisional application number
60/16,901, filed Decembex 3, 1999.
Field of the Invention
The present invention is directed to wireless communication, and more
particularly to
asset location and tracking systems.
Background and Summary of the Invention
Businesses have an ongoing need to track and inventory assets. This is
particularly
l0 critical for high-value assets such as in porfiable communications test
equipment used by the
telecommunications industry. When valuable equipment is portable, it is
susceptible to theft, as
well as loss or misplacement. Because such equipment may be used at remote
locations outside
the premises of the business, conventional security measures such as locking
down equipment
and guarding against its removal axe impractical.
15 In addition, even where security is not a concern, equipment maybe
misplaced and not
locatable when needed, even if safely stored on the proper premises, leading
to increased
equipment costs to ensure an adequate inventory. Also, some equipment may
include specialized
hardware and software that may have different versions, different update
status, and different
compatibility for different uses. It may be difficult for an inventory system
to monitor the
20 particular characteristics of each item, so that the most appropxiate item
can be located, or so that
deficient items can be efficiently located for updating.
Systems have been proposed to track assets using global positioning system
(GPS)
signals, with cellular transceivers reporting the assets' locations. While
possibly suited for some
applications, these are not useful for areas where GPS signals do not reach,
such as the intexior of
25 most buildings where many types of assets are most likely to be found.
The pxesent invention overcomes the limitations of the prior art by providing
a
communication module for an asset to be monitored. The module operates to
periodically
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receive a signal from a monitoring facility via a first wireless communication
system, and in
response to the absence of the signal at an expected time, communicating with
the module via a
second wireless system. The first system may be a short range system operating
inside a
limited facility, and the second system may be a cellular phone system. The
module may
include a global positioning receiver, so that the module may report its
location via the
second system to the monitoring system when it is taken from the transmission
range of
the first system.
Brief Description of the Drawings
Figure 1 is a high-level block diagram showing the environment in which the
facility
1 o preferably operates.
Figure 2 is a schematic block diagram showing an instrument tracking module
according
to a preferred embodiment of tl2e invention.
Detailed Description of a Preferred Embodiment
Figure 1 shows an asset tracking system 10 operating both internally to and
externally of
15 a user entity's physical facility 12. The facility may be one or more
buildings, such as
warehouses, or open areas in a limited space, normally private or restricted
property controlled by
the user. The facility contains a short range wireless communication system
having one or more
base transceiver stations 14 that are installed in the facility in sufficient
numbers and distributed
locations to provide full wireless communication coverage for the entire
interior of the facility.
20 Each base station 14 includes a transceiver and antenna 16, and a
controller 20. The
controllers are connected to a central computer 22 in the facility, or
connected to the components
in the facility. The computer 22 is connected to a telecommunication network
24, such as
provided by the Internet, an internal network, or a public switched telephone
network. A number
of equipment assets 26 to be tracked may be located anywhere, inside of or
outside of the facility.
25 As will be discussed below, each of these assets includes a communication
module that
communicates with the facility transceivers I4, with a cellular network 30
connected to the
telecommunication network, and with a satellite-based global position system
(GPS) 32. A
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monitoring center 34 connected to the network 26 receives and coordinates
communications
from the asset modules.
The facility's internal wireless communication system is preferably a radio
frequency
system operating on a 2.4 GHz ISM (Industrial, Scientific, Medical) frequency
band designated
by the FCC as a license-free band. This provides broadcast and reception range
of about 1000
feet, so that larger facilities may require more than one base station. An
advantage of this mode
is that the low power spread spectrwn transceivers do not affect nearby
equipment that might
otherwise be susceptible to radio frequency energy generated in other modes,
such as by cellular
transmitters. Depending on the configuration of the facility, more base
stations may be required
to if the space is subdivided into rooms by walls that impede transmission of
signals. In alternative
embodiments, different frequency bands may be employed. For applications in
which the assets
are large and generally visible in an open space, visible or infrared line-of
sight transmissions
may be used. Such a system is better suited for tracking large equipment such
as heavy
machinery or large manufactured goods than for the smaller portable electronic
assets of the
preferred embodiment.
Figure 2 shows a portable electronic equipment asset 26, which includes a
tracking
communication module 36. The module includes a short range transceiver 40 and
associated
antenna 42 that communicate with the facility base stations I4 when the asset
is in the facility. A
cellular transceiver 44 and associated cellular antenna 46 operate to
communicate with the
2o cellular system 30 when the asset is outside ofthe facility. A GPS receiver
SO and associated
antenna S2 operate to receive signals from satellites 32, from which the
receiver calculates its
location.
A controller S4 includes microprocessor circuitry programmed to coordinate
communication by each of the above elements, and may be integrated with or
connected to other
circuitry in the asset. Such integration may be used so that the controller
disables or enables the
asset function depending on communication status (e.g. disabling the device if
taken out of an
authorized area by a presumed thief.) The controller may also read information
from the device,
including asset configuration, identifying number, asset options, software
revision level, and
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hardware revision level, so that one of the transceivers can report this
information to the central
system. This permits the system to generate benefits other than security and
inventorying. For
instance, calibration and updates may be scheduled, either centrally, or by a
report generated in
the asset that a calibration or update is due.
The module includes a dedicated rechargeable battery S6 that powers the module
when
the asset is discomlected from an external power source. A charger 60 is
connected to the device
power supply to charge the battery when the device is connected to power for
normal operation.
In the preferred embodiment, the short range transceiver 40 includes a 2.4 GHz
modem.
The cellular transceiver 44 may essentially consist of CDMA, TDMA, GSM or AMPS
cellular
1o telephone circuitry, with an analog modem converting digital signals to and
from the controller
into analog signals transmissible via cellular transmission. The circuitry of
the communication
tracking module 36 is shown as having separate components for each function.
However, the
various functions may integrated onto fewer components to reduce size and
cost. Further, the
module components may be integrated with other circuitry of the asset, at
least in part as a
security measure against unauthorized disablement or removal of the tracking
circuitry.
Operation
The facility central computer 22 operates to regularly poll all assets in the
facility to
verify their presence. A polling signal is sent out to each of the assets,
which reply with
identifying information. Alternatively, the system may send out a single call
for reports from the
2o assets, which may reply sequentially or simultaneously. The reply may also
include location
ir~fonnation enabling the asset to be located within the facility, as well as
other device status
information noted above. Different devices may be polled at different selected
intervals, and
polling may be conducted automatically, or manually, such as in response to a
user's need for a
particular type of asset.
Each asset may operate using receipt of the polling signal as an optional
"keep alive"
signal, so that the asset is disabled if it does not receive the signal. Thus,
a device that has been
taken from the facility is disabled until it is returned. For devices
requiring authorized use
outside the facility, an authorization code may be entered to permit operation
(this may be
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integrated with verification measures associated with remote cellular
commuiucation discussed
below.)
If an asset is removed from the facility so that it is out of communication
with the short
range wireless system, it may be programmed to respond in several different
ways, which may be
employed separately or in combination. As noted above, it may disable itself
in the absence of a
"keep alive" signal.
Preferably, upon removal from the facility, the module responds to the lack of
an
expected polling signal at a selected time by initiating a cellular telephone
transmission to the
monitoring center. The call may be delayed any amount of time as needed. For
some assets, an
to immediate call may be appropriate to prevent theft. For other assets
routinely taken from the
facility and normally returned within limited time period, a delay may be
appropriate (e.g. a
checked out municipal bus might not report its location until after the end of
the expected shift,
so that normal use does not trigger a cellular report, but failure to return
promptly does.) The
monitoring center may be a central agency serving many different independent
users, or which
may be on the site of the user, and connected directly to or integrated with
the control computer
22.
Either automatically, or upon request by the monitoring authority, the module
controller
may activate the GPS circuitry to establish the current location of the asset,
and transmit this
location information to the monitoring center. This permits the asset to be
recovered in the event
of theft. In typical cases, such as when the asset has been removed as a part
of routine business,
the location may be checked against expected authorized locations. Such
locations may be stored
in a database to reflect corridors of authorized transport, remote locations
of authorized use and
storage, and trip or relocation plans entered in advance by personnel
intending to make
authorized transport.
As an alternative to the module automatically initiating cellular
communication in the
absence of the facility signal, the device may remain passive, so that action
must be taken by the
tracking computer. Essentially, the system calls the cellular transceiver of
the missing asset to
receive a report of its whereabouts. This has the disadvantage of requiring
the cellular phone to
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be powered up fin a receiving mode, depleting batteries. However, conservation
measures such
as cycling the receiver on only at periodic intervals known to the system
limit power
consumption.
In this case, the tracking computer is alerted by the absence of a response to
the short
range wireless signal in the facility. Consequently, the tracking system may
take action to track
down the asset. In cases where the asset is expected to be out of the facility
for a pre-established
period of time (such as if it is checked out for a temporary off site job),
the computer may take
no action, unless the device does not return as expected. This strategy is
suitable for users having
multiple facilities between which assets are transported, where each facility
has ifs own soxt
1o range wireless tracking system. In such cases, the computer may allow a
grace period for the
device to return to a facility, before initiating cellular location efforts.
These techniques are also
applicable to the active module approach discussed above, in which the module
initiates cellular
communication in the absence of the facility signal.
Another operating mode provides a virtual "fence" within which the asset may
tolerably
be located, and outside of which it is not permitted to be moved. This fence
may be
preprogrammed into the controller as acceptable location values to be
generated by the GPS unit.
When GPS-generated location values depart from the acceptable domain, a
cellular reporting call
is initiated.
The module may include safeguards that disable the asset if it is kept out of
cellular range
2o for more than a selected period of time. For instance, to prevent a thief
from secreting and using
an asset in a shielded or remote area away from cellular coverage (assuming
the absence of a
keep-alive system), so that the owner could not located it via the
GPS/cellular link, the device
may be programmed to become disabled. An extended grace may be allowed, so
that an
authorized user may temporarily use the asset in a remote or shielded
location. For extended use
away from cellular coverage, a wired telephone line may be connected to the
module to report
location information, and to enable any keep-alive signals to be transmitted
from the monitoring
center.
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Additional functionality may include using the wireless transport to provide
software
upgrades to the device; provide "data downloads" to the device that may update
certain
configuration information of the device. Other remote diagnostics could also
take place during
the connection to the wireless network.
While the above is discussed in terms of preferred and alternative
embodiments, the
invention is not intended to be so limited. For instance, instead of the two
illustrated modes of
communication (short range radio frequency and cellular frequencies), other
communication
modes may be used. These may include email, pager, satellite modes, in
addition to other local
transmission modes such as the optical modes discussed above. The modules may
include other
1o security features, such as motion, video and audio sensors that allow
transmission of additional
infounation about the envirorunent into which the asset has been taken. Such
information may
be used to prosecute wrongdoers, and to deter future wrongdoing. Various
combinations of the
different features above may be employed without departing from the concept of
the invention.
