U.S. patent application number 12/962848 was filed with the patent office on 2011-04-21 for asset management device and method using simplex satellite transmitter augmented with local area transceiver.
Invention is credited to Gary Naden, Scott Quillin, Stephen Schamber, Ronnie Tanner.
Application Number | 20110090041 12/962848 |
Document ID | / |
Family ID | 34226288 |
Filed Date | 2011-04-21 |
United States Patent
Application |
20110090041 |
Kind Code |
A1 |
Naden; Gary ; et
al. |
April 21, 2011 |
Asset Management Device and Method Using Simplex Satellite
Transmitter Augmented with Local Area Transceiver
Abstract
A device, method, and computer program product for monitoring
and transmitting a location and a local status of a remote device
using a satellite transmitter is provided. The monitoring device
includes a position location unit, a satellite transmitter, a power
source, a controller, and a short-range radio transceiver. The
position location unit is configured to determine a location of the
remote device. The satellite transmitter is configured to transmit
the location to one or more satellites in low earth orbit. The
controller includes a power management unit configured to control a
power state of the position location unit and the satellite
transmitter, and to periodically enable and disable power from the
power source to the position location unit and the satellite
transmitter. The short-range radio transceiver is used to configure
and remotely manage the monitoring device and is used by the
monitoring device to monitor local sensors wirelessly.
Inventors: |
Naden; Gary; (Mandeville,
LA) ; Tanner; Ronnie; (Covington, LA) ;
Quillin; Scott; (Mandeville, LA) ; Schamber;
Stephen; (Metairie, LA) |
Family ID: |
34226288 |
Appl. No.: |
12/962848 |
Filed: |
December 8, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11480793 |
Jul 3, 2006 |
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12962848 |
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10656133 |
Sep 8, 2003 |
7099770 |
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11480793 |
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Current U.S.
Class: |
340/3.1 |
Current CPC
Class: |
G01S 5/0027 20130101;
G06Q 10/06 20130101; G06Q 10/087 20130101; G06Q 10/08 20130101;
G08G 1/20 20130101; G06Q 50/28 20130101; G01S 19/34 20130101 |
Class at
Publication: |
340/3.1 |
International
Class: |
G05B 23/02 20060101
G05B023/02 |
Claims
1. A monitoring device configured to monitor a remote status of
mobile assets, comprising: a position location unit to determine a
location of a remote device; a simplex satellite transmitter
configured to transmit the location to one or more satellites; a
power source; an external interface for communicating with one or
more devices; a controller in communication with the external
interface and including a power management unit configured to
control a power state of the position location unit and of the
simplex satellite transmitter; and wherein the controller is
further configured to control the position location unit to
determine the location and to control the simplex satellite
transmitter to transmit the location based on the interval
schedule.
2. The monitoring device of claim 1, wherein the position location
unit comprises a GPS receiver subsystem.
3. The monitoring device of claim 1, wherein the power management
unit is further configured to control a power state of the external
interface and to periodically enable and disable power from the
power source to the external interface.
4. The monitoring device of claim 1, wherein the external interface
includes at least one of a plurality of alarm inputs.
5. The monitoring device of claim 1, wherein the external interface
includes a configuration interface configured to receive
modifications to configuration parameters.
6. The monitoring device of claim 5, wherein the power management
unit is further configured to control a power state of the
configuration interface and to periodically enable and disable
power from the power source to the configuration interface.
7. The monitoring device of claim 1, wherein the external interface
includes an external data unit configured to receive external
data.
8. The monitoring device of claim 7, wherein the power management
unit is further configured to control a power state of the external
data unit and to periodically enable and disable power from the
power source to the external data unit.
9. The monitoring device of claim 1, wherein the external interface
includes at least one of a wired or wireless interface.
10. A monitoring device for monitoring a remote status of a mobile
asset, the monitoring device comprising: a position location unit
to determine a location of a remote device; a satellite transmitter
to transmit the location to one or more satellites; an external
interface for communicating with one or more devices; a power
source; and a controller in communication with the external
interface and including a power management unit configured to
control the supply of power from the power source to the satellite
transmitter on an interval schedule.
11. The monitoring device of claim 10, wherein the position
location unit comprises a GPS receiver subsystem.
12. The monitoring device of claim 10, wherein the external
interface includes at least one of a wired or wireless
interface.
13. The monitoring device of claim 10, wherein the power source
comprises a battery.
14. The monitoring device of claim 10, wherein at least one of the
one or more satellites operate as a bent-pipe relay device.
15. The monitoring device of claim 10, wherein the external
interface includes at least one of an alarm input, a configuration
interface configured to receive modifications to configuration
parameters, and an external data unit configured to receive
external data.
16. The monitoring device of claim 10, wherein the external
interface is periodically enabled by the power management unit to
communicate with one or more devices.
17. The monitoring device of claim 10, wherein the external
interface is used to modify an operating configuration of the
monitoring device.
18. The monitoring device of claim 10, wherein the external
interface is used to monitor one or more sensor devices.
19. The monitoring device of claim 10, wherein the external
interface is used to relay information received from one or more
devices.
20. The monitoring device of claim 18, wherein a sensor is at least
one of a door sensor, a cargo sensor, a dry contact circuit closure
sensor, a temperature sensor, an analog voltage sensor, an analog
measurement sensor, a volume sensor, a pressure sensor, or a
humidity sensor.
21. The monitoring device of claim 10, wherein the external
interface detects a remote sensor and initiates a satellite
transmission.
22. The monitoring device of claim 21, wherein the satellite
transmission contains data from at least one of the remote sensor,
the monitoring device, and the position location unit.
23. The monitoring device of claim 10, wherein the controller is
further configured to control the position location unit to
determine the location and to control the satellite transmitter to
transmit the location based on the interval schedule.
24. The monitoring device of claim 10, wherein the interval
schedule is at least one of a repeated fixed interval, a set of
fixed intervals sequentially executed and repeated as a set, or an
interval which is randomly or pseudo-randomly adjusted over
time.
25. The monitoring device of claim 15, wherein the controller is
configured to detect at least one of the plurality of alarm inputs,
and upon detection of an alarm input, to cause the satellite
transmitter to transmit alarm data.
26. The monitoring device of claim 15, wherein the controller is
configured to detect at least one of the plurality of alarm inputs,
and upon detection of an alarm input, to enable power to the
satellite transmitter and to the position location unit, and to
cause the position location unit to determine the location and to
cause the satellite transmitter to transmit the location and alarm
data.
27. The monitoring device of claim 15, wherein the controller is
configured to detect at least one of the plurality of alarm inputs,
and upon detection of an alarm input, to enable power to the
external interface.
28. The monitoring device of claim 10, wherein the controller is
configured to detect modifications to a configuration parameter,
and upon detection of modifications to the configuration parameter,
to modify operation in accordance with the configuration
parameter.
29. The monitoring device of claim 10, wherein the controller is
configured to detect external data from a device, and upon
detection of external data, to cause the satellite transmitter to
transmit the external data.
30. The monitoring device of claim 10, wherein the controller is
configured to queue transmissions to the satellite transmitter and
to control the satellite transmitter to transmit the queued
transmissions as a block.
31. The monitoring device of claim 10, wherein the controller is
configured to control the satellite transmitter to periodically
transmit a health status of the remote device.
32. The monitoring device of claim 10, further comprising a motion
detection unit.
33. The monitoring device of claim 32, wherein the controller is
configured to cause the position location unit to determine the
location and to cause the satellite transmitter to transmit the
location upon detection of motion by the motion detection unit.
34. The monitoring device of claim 32, wherein the controller is
configured to cause the satellite transmitter to transmit a motion
detection message upon a determination by the motion detection unit
of a stop of motion followed by a start of motion.
35. The monitoring device of claim 32, wherein the controller is
configured to cause the satellite transmitter to transmit a motion
cease message upon a detection by the motion detection unit of a
start of motion followed by a stop of motion.
36. The monitoring device of claim 10, wherein the power management
unit is configured to disable power and then enable power to the
satellite transmitter on a duty cycle of less than a 1% power-on to
power-off ratio
37-45. (canceled)
46. A configuration tool for configuring one or more host satellite
asset management devices using a wireless interface, wherein a host
satellite asset management device includes a position location unit
to determine a location of a remote device, a satellite transmitter
to transmit the location to a satellite, and an external interface
for communicating with the configuration tool.
47. The configuration tool of claim 46, wherein the configuration
tool provides for the configuration of a reduced set of host
satellite asset management devices, with the reduced set based on
data derived from the whole set of detected host asset management
devices.
48. The configuration tool of claim 46, wherein the configuration
tool configures at least two of the host satellite asset management
devices simultaneously.
49. The configuration tool of claim 46, wherein the configuration
tool configures one or more remote sensor devices.
50. A gateway device for controlling one or more host satellite
asset management devices, the gateway device comprising: a wireless
interface compatible with at least one of a host satellite asset
management device or a remote sensor device; and a controller
device to control the wireless interface for communicating with a
host satellite asset management device or a remote sensor
device.
51. The gateway device of claim 50, wherein at least one of a host
satellite asset management device or the gateway device comprises:
a position location unit to determine a location of a remote
device; a satellite transmitter to transmit the location to one or
more satellites; an external interface for communicating with one
or more devices; and a power source.
52. The gateway device of claim 50, wherein the controller device
is further configured to detect new and exiting host satellite
asset management devices and to communicate a change of device
configuration based on proximity to the gateway device.
53. The gateway device of claim 50, wherein the controller device
is further configured to detect a host satellite asset management
device and to configure the detected host device for low power
operation while in proximity to the gateway device.
54. The gateway device of claim 50, wherein the gateway device
announces its presence to a host satellite asset management device
and wherein the host satellite asset management device alters its
mode of operation while in proximity to the gateway device.
55. The gateway device of claim 50, wherein the controller device
is further configured to relay information from nearby host
satellite asset management devices to other gateway devices.
56. The gateway device of claim 50, wherein the gateway device
further comprises a communication interface for communicating with
a remote system controller interface.
57. The gateway device of claim 56, wherein the controller device
is further configured to monitor nearby host satellite asset
management devices and to relay data from the nearby host devices
to the communication interface.
58. The gateway device of claim 56, wherein the communication
interface is at least one of a wired or wireless interface.
59. An interrogator device comprising: a wireless interface; and a
controller which monitors and detects the presence of one or more
host asset management devices, and upon detection of a host device
binds to and initiates a function that results in the host device
transmitting a satellite message.
60. The interrogator device of claim 59, wherein the transmitted
satellite message contains at least one of location information,
interrogator identification information, or interrogator
information.
61. The interrogator device of claim 59, wherein at least one of
the interrogator device or the host satellite asset management
device comprises: a position location unit to determine a location
of a remote device; a satellite transmitter to transmit the
location to one or more satellites; an external interface for
communicating with one or more devices; and a power source.
62-72. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S.
application Ser. No. 10/656,133, filed on Sep. 8, 2003, which is
herein incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to the monitoring of mobile
and remote endpoint devices over a very large area of service.
BACKGROUND OF THE INVENTION
[0003] Asset management is a critical part of any business entity
engaged in the transfer of raw or finished goods. It is important
to carefully manage re-supply of raw materials to ensure that the
manufacturing or service element of an industry does not halt and
to carefully manage transportation of finished goods to minimize
inventory held for sale. Those companies that do not optimize
manufacturing and materials handling are at a significant
disadvantage.
[0004] The proliferation of location based services, devices, and
methods in the past decade is a testimony to the market need for an
effective means for locating and managing remote assets that are
fixed or mobile. There exist several methods for collecting remote
data wirelessly, including terrestrial and satellite based
communications systems. The problem arises in collecting data from
assets that do not have readily available power, such as cargo
trailers, rail, and remote fixed assets such as pipelines, shear
sensors, and the like.
[0005] The uncertainty associated with raw materials and finished
goods in transit presents a problem in asset management. Companies
generally operate with an element of uncertainty as to the exact
time of delivery or location of pending delivery for products and
raw materials in transit. Unforeseen conditions impacting the
arrival of truck, rail, or other vessel deliveries are impossible
to predict and difficult to model. Real-time information about
materials in transit can be used to forecast deliveries, schedule
manpower and other materials, and predict finished goods inventory
supply.
[0006] The transportation industry suffers from in-transit cargo
theft and loss. Loss of cargo happens in a wide variety of ways,
from employee/driver theft to the organized capture of entire
fleets of trailers and rail-cars. The transportation industry has
been struggling to limit loss through radio communication means.
The cellular telephone industry has enabled a host of
communications products that are making an impact. These products
provide many functions such as standard voice communication, data
services, and real-time position reporting and status of vehicle
operations such as speed, temperature, or brake conditions.
[0007] Conventional solutions typically rely on cellular
communication systems or satellite communication systems. Existing
technology solutions that rely on cellular coverage are generally
not ubiquitous in coverage. Cellular coverage may be adequate for
urban and major interstate routes but becomes unreliable in rural
or sparsely populated regions. Additionally, a cellular network
implemented primarily for voice communications is a poor solution
for rail or vessel data communication. Also, as cellular technology
advances, the protocols have transitioned from analog to digital
and now to tri-band Global System for Mobile Communication (GSM).
Thus, some communication systems developed only a few years ago are
already obsolete.
[0008] Cellular communication asset management systems are
inherently two-way in nature and thus require continuous line power
for operation. This type of system does not operate effectively on
battery power without periodic reconnection to line power such as
an automotive power system.
[0009] Satellite based communication systems mitigate some of the
problems associated with cellular asset management devices. For
instance, satellite modems are not limited to the service coverage
area of cellular telephone corridors. Instead, the area of service
is related to the satellite system selected for use and thereby
solves the problem of rural and vessel coverage.
[0010] Satellite asset management systems are preferred if the
communication system can provide adequate information bandwidth to
support the application requirements. Generally, satellite asset
management systems are the successors of cellular systems and offer
broadband feature sets such as Internet and voice over
Internet-Protocol. Broadband satellite services are typically
expensive and generally prone to communication failures due to
weather and obstruction. Most asset management systems which
utilize broadband satellite must package broadband services such as
voice or Internet in order to justify the cost of the data
bandwidth, even though the information for asset management is
generally low-bandwidth in nature. This drives the cost of
satellite-based asset management systems up.
[0011] The transmit power required to communicate to geo-stationary
satellites imposes power system problems for a remote asset
management device. Existing satellite asset management systems
generally must incorporate transmit power amplifiers of up to 10
Watts to adequately operate. As most satellite communication
systems impose tightly controlled spectral masks, digital
communication systems must incorporate linear or nearly linear
(Class A or Class AB) power amplifier architectures to prevent
spectral re-growth. As a result, the transmit device must be
designed to produce up to 10 Watts with amplifier architectures
which are typically only 40% efficient. This creates difficult
design limitations which require sufficient line power or
high-density bulky battery systems to function.
[0012] Most satellite-based asset management systems use satellite
architectures that are duplex in nature. In order to send data over
a satellite, the remote device must generally negotiate a data
channel. Even if the data is only one-way in nature, the
communication modem must contain both receive and transmit
capability to implement this negotiation. Remote asset management
devices must both listen and transmit in order to facilitate data
transfer to and from a remote device.
[0013] Both cellular and two-way satellite asset management systems
require available line power or extensive battery systems to
operate. Even existing systems equipped with low power operational
states must utilize excessive power to manage two-way
communications as well as transmit with sufficient energy to
operate within the communications infrastructure.
[0014] Existing asset management devices are generally located on
the tractor-cab of the truck, train, or vessel. This serves to
locate the cargo while the load is attached. Unfortunately, when a
load such as the trailer, rail-car, or barge is disconnected, the
important information that provides value for asset management is
lost. Trailers that get dropped-off by a driver may become lost for
hours or days, resulting in the total loss of perishable loads or
missing deadlines for non-perishable loads. Thus, inventory
management becomes difficult and highly labor intensive to minimize
misplaced loads.
[0015] Rail-car tracking systems generally lag in capability behind
truck tracking systems. Since rail-cars remain on class 1 lines,
the owners typically know when the rail-cars have passed
checkpoints using barcode or visual identification systems.
However, once the rail-cars are placed on class 2 or class 3 lines
there is generally no real-time tracking. Additionally, customers
often use rail-cars as temporary storage to delay offloading goods
and maintain an average amount of storage of goods at the cost of
the rail-fleet owner. Rail-fleet owners have a difficult time
assessing demurrage charges because they may not know if the
rail-car has been offloaded on schedule or where the rail-car is
currently located. As a result, the only solution generally applied
is to add new cars to the fleet to satisfy logistic problems of
moving goods.
[0016] Barge and vessel owners generally are dependent on river
pilots and deep-sea vessel operators for the location of goods
using voice communication only. As such, commodity traders usually
maintain a staff of logistics personnel to voice-track products as
they are moved. A radio-telemetry product that works without a
cellular infrastructure and without the requirement of available
power can thus dramatically reduce the reliance of pilots and
logistics staff.
[0017] There is thus an unmet need in the art for an asset
management device that operates on an internal battery and provides
years of service, utilizes satellite communication with a
world-wide footprint, integrates Global Positioning Satellite
service (GPS) providing world-wide location determination, utilizes
remote configuration, and which provides for external data such as
alarms and raw user data, enabling sophisticated endpoint
monitoring.
SUMMARY OF THE INVENTION
[0018] It is a first object of this present invention to enable
simplex transmitters for remote configuration through the use of an
external interface, which can be a wired or a wireless interface
such as a short-range radio transceiver interface. The present
invention provides a system and method whereby the introduction of
an external interface is extremely power efficient while providing
utility of function. The present invention also provides a system
and method whereby use of the external interface is extremely power
efficient, and does not significantly impair the overall service
life of the battery operated remote asset management device.
[0019] The introduction of an external interface introduces many
new utilities as well as overcomes a significant shortcoming of the
prior art. Since a simplex satellite transmitter is one-way, it is
dependent on internally or locally initiated stimuli to engage
alternate functional modes. For example, since it is not possible
to talk to a remote asset management device that is field deployed,
it is impossible to instruct such a device to alter a report
schedule or initiate an extended low power state. Thus, it is an
additional object of the present invention to provide an external
interface to provide configuration, sensor monitoring, group
detection and control, and long-range detection and control of host
satellite asset management devices. The addition of the external
interface, operating in a power efficient mode, serves to overcome
deficiencies in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The foregoing and other advantages and features of the
present invention will become more apparent from the detailed
description of exemplary embodiments of the invention given below
with reference to the accompanying drawings.
[0021] FIG. 1 is a block diagram of a battery powered remote
endpoint asset management device capable of ascertaining its
location and relaying the location to an external satellite
network.
[0022] FIG. 2 is a block diagram of a battery powered remote
endpoint asset management device with additional functionality
including the external interface shown as a short-range radio
transceiver interface according to one embodiment of the present
invention.
[0023] FIG. 3 is a block diagram of a battery powered remote
endpoint asset management device with the additional functionality
of a power efficient mode of operation for the short-range radio
transceiver interface of one embodiment of the present
invention.
[0024] FIG. 4 is an operational illustration of the use of a
configuration tool enabled with a short-range radio transceiver
interface used to configure one or more remote host satellite asset
management devices according to one embodiment of the present
invention.
[0025] FIG. 5 is an operational illustration of the use of a
configuration tool enabled with a short-range radio transceiver
interface used to configure one or more remote sensors to be
monitored by a host satellite asset management device according to
one embodiment of the present invention.
[0026] FIG. 6 is an operational illustration of the use of a
gateway device enabled with a short-range radio transceiver
interface used to configure one or more remote host satellite asset
management devices or one or more remote sensors according to one
embodiment of the present invention.
[0027] FIG. 7 is an operational illustration of the use of a remote
controller used to control one or more gateway devices, each with a
short-range radio transceiver interface used to configure one or
more remote host satellite asset management devices according to
one embodiment of the present invention.
[0028] FIG. 8 is an operational illustration of the use of an
interrogator device used to initiate a satellite transmission from
of one or more remote host satellite asset management devices
according to one embodiment of the present invention.
[0029] FIG. 9 is an operational illustration of the use of one or
more gateway devices to relay data from one or more remote host
satellite asset management devices in one embodiment of the present
invention.
[0030] FIG. 10 depicts the communication method for a power
efficient short-range radio transceiver interface used in the
remote host satellite asset management device of one embodiment of
the present invention.
[0031] FIG. 11 depicts the communications interface between a
remote host satellite asset management device and a slave device in
one embodiment of the present invention.
[0032] FIG. 12 further defines the control registers used for
managing the interface described in the embodiments of FIGS. 10 and
11.
[0033] FIG. 13 depicts operation of the short-range transceiver
link using gateway and repeater devices in one embodiment of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] Referring now to the drawings, wherein like reference
numerals designate identical or corresponding parts throughout the
several views, preferred embodiments of the present invention are
described.
[0035] FIG. 1 illustrates the functional blocks of a battery
operated endpoint device for remote asset management as described
in U.S. Patent Application Publication Number 20050171696, which in
turn references U.S. Pat. No. 4,977,577 and U.S. Pat. No.
5,987,058, each assigned to the assignee of the present
application, Axonn LLC, and each incorporated by reference
herein.
[0036] Enclosure 102 depicts the physical enclosure of the asset
management device. Internal to the enclosure 102 is a battery 107
used to power the location determination device 103. The location
determination device 103 may be any means in the art for
ascertaining the location of the endpoint device. For example, the
location determination device 103 may derive the location using
inertial navigation, barcode scan for waypoints, radio telemetry
for fixed waypoints, or satellite data. Once the location has been
ascertained by a location determination function, the location
information is transmitted using a satellite transmitter 104 to the
satellite system 105. This transmission function may be
accomplished using any number of satellite communications means,
such as a simplex satellite transmitter. Simplex communication as
known in the art is a form of one-way communication that provides
for a transmit or a receive path between two network components.
The efficiencies of a simplex one-way satellite transmitter may be
utilized to send data to a satellite constellation for relay to a
ground receiver or network. The data may be distributed from the
receiver gateways to end users using a variety of other terrestrial
communication networks, such as the Internet. Battery 107 is a
power source local to the device and provides power to the remote
asset management device.
[0037] The embodiment of the present invention as shown in FIG. 2
adds several capabilities to the remote asset management device of
FIG. 1. The addition of an external interface having a short-range
radio transceiver overcomes many obstacles associated with use of a
simplex satellite transmitter to manage assets. While an external
interface having a radio frequency transceiver is described in
various embodiments of the present invention, one of skill in the
art will understand that the external interface can use any
wireless frequency. One of skill in the art will also realize that
the host controller 307 can be connected to one or more external
interfaces, which can be collectively referred to as the "external
interface." As described in various embodiments of the present
invention, the external interface can have one or more wired or
wireless interfaces, including a wireless external interface using
radio frequency such as the short-range transceiver 308. For
convenience only and to help illustrate the novelty of various
embodiments of the present invention, the short-range transceiver
external interface 308 may be discussed or illustrated as a
separate physical or logical unit, such as item 308 in FIG. 3.
Thus, while illustrated or discussed separately, one of skill in
the art will realize that the short-range transceiver 308 is simply
one type of external interface useable with embodiments of the
present invention.
[0038] In FIG. 2, the remote asset management device 202 contains a
location determination device such as a GPS receiver 203 which
receives signals from the GPS satellite constellation 201. Location
determination may also be accomplished in a variety of ways, with
GPS employed in various embodiments. The satellite transmitter 204
relays information about the remote asset management device 202 to
the satellite constellation 205. The satellite transmitter can be a
two-way transmitter. The current embodiment utilizes a simplex
transmitter. The short-range radio transceiver 208 is used by the
asset management device 202 to communicate terrestrially to a
remote device similarly enabled with a compatible radio
transceiver.
[0039] Remote asset management device 202 includes a host interface
controller 206 which performs several functions that add utility to
the endpoint device. The primary function of the host interface
controller 206 is power management. Thus, the host interface
controller 206 can contain an algorithmic engine capable of
enabling and disabling the functional blocks of the remote asset
management device 202. The host interface controller 206 can
therefore connect the battery 207 of the remote asset management
device 202 to the GPS receiver 203, the satellite transmitter 204,
and the short-range transceiver 208 to perform power management
functions as necessary, such as disabling all functionality to set
the unit 202 into a low power state. While in a low power state,
the host interface controller 206 will use a variety of means to
resume active power mode to perform the asset management
function.
[0040] FIG. 3 provides another embodiment of the present invention
useful for asset management. As in FIG. 2, the present embodiment
is contained in an enclosure 302 suitable for numerous
applications. The enclosure 302 in the present embodiment is
designed to withstand the harsh environment of outdoor use for
extended periods of time. The device retains the principal
functions of location determination 303 derived from the satellite
system 301, a satellite transmission means 304, a short-range radio
transceiver 308, a battery 306, and a host controller 307. The host
controller 307 includes hardware or algorithmic means to accomplish
the functions depicted in the controller block. The controller 307
performs power management functions, placing the asset management
device in reduced power states and resuming operational functions.
The controller 307 may use the timer function to periodically or
randomly engage operation. It may also use the event table or
alternate event table or a combination of each to schedule
operational functions. The controller 307 may include alarm
detection means to initiate an unscheduled operational function.
The controller 307 may include an external interface used by an
external device to initiate an unscheduled operational function.
Finally, the controller 307 may use a motion detection means to
initiate an operational function. These controller 307 functions
may also be used in various combinations to enable complex
operational functions. The controller 307 functions can include a
satellite transmission event and a local communication event via
the short-range transceiver 308 means.
[0041] The current embodiment of the present invention can include
external interfaces 309 used to bridge the communication between
the controller 307 and any combination of external alarms,
configuration devices, or communications devices. Additionally, the
present invention may also include an optional power input 310 used
to extend or replace the internal battery 306 function.
[0042] The short-range radio transceiver can be power managed to
prevent undue degradation of service life through exhaustion of
battery 306. FIG. 3 also depicts a data storage element 311 which
provides for data logging of the asset management device 302.
[0043] Data may be generated by the controller or received from
remote sensors or data interfaces via the wired serial interface or
over the wireless short-range transceiver interface 308.
[0044] FIG. 4 shows one embodiment of the present invention which
does not require physical connection to an asset management device
403 for configuration. FIG. 4 depicts this function where the asset
management device 403 incorporates the internal means and functions
enclosed in 302. The short-range radio transceiver function 403 can
be used to communicate with a configuration tool 405. The
configuration tool 405 need only be in relative proximity to the
asset management device 403 to configure it. Since the radio link
is bidirectional, the configuration tool 405 can query the asset
management device identification information to determine the
precise device being configured. Similarly, the configuration tool
405 can communicate with one or more asset management devices 403,
404 within range of the short-range radio transceiver link. The
configuration tool 405 can query each unique identification term
and present them to the operator for individual or group selection.
In this way, an operator may configure devices at depot maintenance
while still in the packing crate, or individually in the initial
configuration. The operator also has the ability to perform query
or configuration functions in the field after the units have been
deployed. Once configured, each unit resumes the operational
functions of asset management as before, using the GPS satellite
network 401 to determine location and relaying long-range data over
the data satellite network 402. The present embodiment can use a
LEO Data Satellite network.
[0045] Additionally, it is an object of the present invention to
utilize a wireless external interface to enable use of wireless
sensors, thus removing the need to install connecting wiring. FIG.
5 depicts both the use of wireless sensors 506 and 507 with asset
management devices 503 and 504 as well as the use of the
configuration tool 505 to properly configure each device. The
sensors 506 and 507 may be any one of a variety of sensors
including door switches, temperature, pressure, volume, dry contact
closure, data logger sensors, and the like. These sensors operate
on their own power, and upon determination of need to relay data to
the asset management device 503 or the system, the sensors pass
sensor data to the asset management device 503. The sensor may be
tightly bound to a specific asset management device using
identification data for each sensor and the asset management
device. Tightly bound sensors send their data only to one asset
management device.
[0046] Alternatively, the sensor may be loosely bound, enabled to
communicate to any asset management device 503, 504 in range of the
transceiver link 506, 507. In this mode, the sensor may be portable
between asset management devices 503, 504. Examples of the utility
provided would be a sensor affixed to a palette or mobile load that
is transferred between trailers, each tagged with an asset
management device 503. The portable sensor would therefore acquire
any suitable asset management device 503 and thus relay data to the
data satellite 502 while in transit. Other similar applications
exist where the sensor must be portable.
[0047] The asset management device 503 may also support a
multiplicity of wireless sensors. The current embodiment can
support many wireless sensors as each sensor can contain a unique
identification data term. The protocol implemented in one
embodiment of the present invention supports up to 32 unique
sensors, allowing for many palettes of cargo tagged with portable
sensors to be monitored by one asset management device 503. Each
sensor such as 506 or 507 would logically connect to a given asset
management device 503 and use that device 503 to relay sensor data
to the data satellite network 502.
[0048] The configuration tool 505 can be used to configure the
sensors 506, 507 for operation either at time of deployment or
subsequently in field use. The configuration tool 505 can configure
an asset management device 503 as described previously by
initiating a communication link and acting as a slave device. The
configuration tool 505 can configure a sensor 506, 507 by
initiating a communication link while acting as a master device
with a reserved identification code that the sensors detect. Under
normal operation the sensor monitors the master communications node
of the asset management device, but can also detect the presence of
the unique identification code of the configuration tool 505, and
upon determining a tool is present could slave to the configuration
tool 505. The configuration tool 505 could then configure the
operational setting of each sensor 506, 507 and then release them
to re-acquire the asset management device serving as the master
communications node for that sensor network. Alternatively, a local
stimulus to the sensor such as a switch or magnet activated relay
switch could trigger the sensor 506 to engage configuration mode
with the configuration tool 505.
[0049] Another object of an embodiment of the present invention is
to provide for automated monitoring and configuration of asset
management devices and sensors through the use of a gateway device
605 as depicted in FIG. 6. The gateway device 605 can be a fixed
asset used to monitor a specific region for the presence of assets
that are equipped with the asset management device 603 or 604. The
gateway device 605 can also be mobile. A single gateway device 605
can monitor one or more asset management devices and also the
sensors 606, 607 that are bound to them. The gateway device 605 can
be an asset management device with an external interface in various
embodiments of the present invention.
[0050] The gateway device 605 may be configured to locally monitor
a region, such as a depot service yard, and to detect the presence
of assets as they arrive in the yard. Upon such detection, the
gateway device 605 can alter the configuration of any or all
detected assets. Such configuration changes may be a change in
reporting, internal functions such as motion detection, mapping,
frequency, or any other operational function local to the asset
management device 603. It may also instruct the asset management
device 603 to enter a low power state, thus reducing the power
utilization and data messaging to the data satellite network 602.
The gateway device 605 may also instruct the asset management
device 603 to engage a low power state while in the presence of the
gateway communications link, and then automatically resume
operation upon detection of removal from the gateway device 605. In
this way, the asset management device 603 can engage a low power
mode and then resume normal reporting functions when the asset
management device is relocated away from the gateway device
605.
[0051] The gateway device 605 may be used in a stand alone
operation for managing short-range transceiver equipped assets 603
within a local region. Alternatively, the gateway device 605 could
include a long-range communications function 608 to enable remote
communications between the gateway device 605 and a remote
controller. A gateway device 605 equipped with a long-range
communications means may be connected to a local network containing
local controllers or other gateway devices. In such a way, the
effective range of the short-range transceiver could be extended
through the use of a multiplicity of gateway devices communicating
over a local network in order to more effectively provide
short-range transceiver capability over an expanded range of
service. A local controller function also connected to the network
could manage each gateway device 605 to properly manage the remote
asset management devices 603, 604 and sensors 606, 607 within range
of the collective gateway devices. This controller function could
reside in either a stand alone controller, or in one or more of the
gateway devices 605 themselves acting as a network master.
[0052] Similarly, the long-range communications interface 608 could
interface to a distant network, interfacing the gateway device 605
to a distant controller or network of controllers. The long-range
communications interface can be a dedicated hard-wired line, public
or private telephone, Internet, long-range wireless such as
cellular, RF data link, satellite, or other similar means. The
gateway device 605 can be controlled by a distant controller
monitoring and controlling the operations of the asset management
devices 603, 604 in range of the gateway device 605. The distant
controller can be an asset management device with an external
interface in various embodiments of the present invention.
[0053] FIG. 7 depicts an embodiment of the present invention for
using local and distant networks and controllers to better manage
and control widely distributed assets tagged with asset management
devices enabled with short-range wireless transceivers. The
long-range communications means of the gateway 705 can enable a
private network where an asset manager could remotely monitor and
control assets abroad. In this embodiment, the network 708 can be
the public telephone network, the Internet, or other means to
connect the distant controller 709 to a local network of asset
management devices 703, 704 within the short-range transceiver
operational range 706. The distant controller 709 can operate on
multiple private and local networks 706, 707.
[0054] Another embodiment of the present invention provides for
public or shared use of widely distributed gateway devices 705,
each networked using the long-range communications means of each
gateway device 705 in each gateway region 706, 707 over a
long-range network 708 to a distant controller 709. In this
embodiment, an asset manager could distribute posted commands for
specific assets to a multiplicity of widely distributed gateway
devices 705. Upon detection of the presence of the desired asset
via the short-range transceiver link to any gateway device 705, the
gateway device 705 can effect a change of configuration in the
remote asset, and subsequently report the change to the central
controller and asset manager. In such an embodiment, multiple asset
managers could use the same network and same distributed gateway
devices 705, accessing shared or unique sets of endpoint assets to
gain widely distributed access to mobile assets. In such a way,
gateway devices 705 widely distributed but networked using their
intrinsic long-range communications means could act as a
back-channel communications means not present in simplex
communications. By intelligently selecting locations for networked
gateway devices 705 such as truck stops, rail yards, interstate
crossings, and high density asset nodes, the asset management
device of the present invention becomes capable of receiving
reconfiguration commands abroad for the majority of operating
devices of a fleet.
[0055] Since each local network can operate with encryption, it is
possible to use the gateway networks in a public manner. Gateway
regions may be established and connected into a central network
controller for use by a multiplicity of separate users or companies
to collectively gain broader regional coverage than attainable
using privately installed networks. Gateways 705 that are used in
this manner can use the encryption keys tied to specific master
identifications to access their own local master networks over any
installed public gateway device 705.
[0056] For example, customers that install their gateway devices
705 to manage their own depot storage regions may connect to a
public network accessible through a web-site over the Internet.
Other companies similarly enrolling in the approach could add their
gateway regions to the public network, such as interstate weigh
stations and truck stops. Both companies may post commands at all
connected gateway devices to perform specific functions for a
unique master identification device upon detection. Once the local
network master is in range of any of the public gateway devices,
the gateway will use the customer supplied encryption key, secured
by the network controller as private to the customer, and access
the local network master to perform the specified function. In this
way, the introduction of other gateway devices to the public
network enables broader and broader control access to mobile asset
management devices. The same architecture discussed as private
using FIG. 7 applies to public use of gateways 705. If the
controller depicted has broad public use, such as a user login with
security, the users may access all gateways 705 connected to the
network independent of the location or real ownership of the
hardware box. The controller and gateways 705 would safeguard the
encryption keys for each user and each local network master
identification using standard user access control. Another
embodiment of the present invention uses the short-range
transceiver capability of each asset management device to initiate
a solicited transmission through an active interrogation function.
FIG. 8 depicts the use of an interrogator device 801 which is a
device enabled with a compatible short-range transceiver suitable
for engaging a compatible asset management device 803. The
interrogator device 801 operates within the effective range of the
short-range transceiver 802. Assets 803 that enter this effective
range are detected by the interrogation device 801, which in turn
establishes a slave communication link to the asset management
device 803. Using the slave communication link, the interrogator
801 can collect data from the asset management device 803 or
trigger it to initiate a satellite function, such as transmit data
to the data satellite 807 or ascertain location using the GPS
satellite 806 and relay that information to the data satellite 807.
The interrogation device 801 therefore functions as a local alarm
input upon detection of an asset management device. The
interrogation device 801 can also contain some history record to
determine if the device in range is a new arrival. One mode of
operation can use the history information to initiate an
interrogation function upon new detection of an asset management
device 803. Another mode of operation would be to interrogate
periodically while an asset 803 is in range 802. Still another mode
of operation would be to interrogate at a range of input power
level or a range based on GPS location to make an entry and exit
interrogation. The interrogator can be an asset management device
with an external interface in various embodiments of the present
invention.
[0057] As depicted in the embodiment of FIG. 8, the in-range asset
management device 803 can be mobile, traveling down a path such as
a road 805. The interrogation device 801 can be a roadside mounted
device, detecting and initiating a GPS location message to the data
satellite network 807. An out of range asset management device 804
would only perform a similar function upon entry into the range 802
of the interrogation device 801. A system as described here would
provide a location and time tag for assets passing a fixed gate or
checkpoint.
[0058] Another embodiment of the present invention enables
extensions of range for the short-range transceiver function
through the use of repeat enabled gateway devices. FIG. 9 depicts a
gateway device 905 functioning in a repeater mode and relaying data
between a multiplicity of asset management devices 903, 904 and the
gateway device 906. In such a manner, the gateway device 906 may be
able to access a wider distribution of asset management devices
than is provided for by the range of the short-range transceiver
function.
[0059] This capability provides utility for assets that are
disadvantageously positioned, such as stacked or loaded in the
holds of ships or strung in lines such as loaded on a train. The
repeater capability allows for a gateway device 906 or devices to
stay in positive communications contact with the distributed asset
903, 904 management devices. The protocol of the short-range
transceiver function incorporates repeat level data to ensure that
repeated messages eventually terminate and thus a repeater will not
continue to repeat a repeated message. Similarly, multiple
repeaters can be used to further extend the effective range and
provide multiple paths for data flow to provide better network
integrity.
[0060] In embodiments of the present invention, the addition of a
wireless interface to the short-range transceiver of the asset
management tool provides powerful enhancements to existing
functions and enables new capabilities. In order for the
short-range transceiver function to work properly, it is necessary
for the power utilization to be minimized in order to preserve the
service life of the battery operated endpoint asset management
devices and sensors. An efficient and innovative protocol is
implemented in the present invention that enables the functions
described herein while minimally impacting the battery life of the
asset management device. The protocol described below causes a
degradation of the product life of a few months over 8 years of
service and requires approximately 10 uA of average current draw on
the primary battery.
[0061] FIGS. 10, 11, and 12 disclose embodiments of the protocol in
use. The protocol and method provide for the creation of local
networks, coexisting open local networks, coexisting closed local
networks, distributed local and closed networks, bound and unbound
sensors, configuration tools, interrogation, repeater, and gateway
devices. A key aspect for each local network is that all devices on
the network may operate predominately in the dormant or off
mode.
[0062] Each local network is managed by a network master. The asset
management device serves as the local network master in one
embodiment of the present invention. Network slaves are devices
that communicate only with the network master. Slave devices in the
present invention are typically sensors, but can be asset
management devices in various embodiments of the present invention.
A key aspect in the present invention is that sensors are
intelligent, performing the prescribed sensing function and using
the network master most often as a communications conduit to the
data system, which is a satellite system in one embodiment of the
present invention. The network master predominately provides for
the easy acquisition of slave devices.
[0063] To accomplish these goals, the network master as depicted in
FIG. 10 continually generates a series of Network Master Idle
Messages 1004 on a periodic basis. Each Network Master Idle Message
1004 contains one or more of the following data terms:
[0064] LEADER: data term used by the receiving device (network
slave) to detect a message start.
[0065] MASTER ID: data term specific and unique to a network master
device. This is the electronic serial number (ESN) of the asset
management device.
[0066] CONTROL REGISTER: contains a set of data terms used to
manage the local network. The Network Master Idle Message Control
Register 1202 is further described in FIG. 12 where the specific
terms contained include one or more of the following:
[0067] CNTRL/Type: a term denoting the device type acting as a
network master.
[0068] CNTRL/Carton Manifest: a term denoting the network master
holds a shipping carton data manifest in memory (used in product
manufacturing packaging and shipping).
[0069] CNTRL/D: a term denoting the network master holds data in a
local data store for collection by external network controller such
as a repeater or gateway device.
[0070] RF Sequence Number: a term that enumerates the specific time
window allocated to the Network Master Idle Message. The network
master increments this sequence number between 0 to 31 and then
repeats the sequence indefinitely. The range of sequence numbers is
not critical to the operation of the method. 32 individual time
slots can be used in one embodiment of the present invention to
facilitate up to 32 different slave devices per network master.
Each slave device may seize an available RF sequence number Time
Division Multiple Access (TDMA) slot for responding to the master
idle message and predominately use this slot for all communications
to the network master. Optionally, a slave device may simply
attempt to communicate on any channel time slot.
[0071] DITHER: a term that denotes the time period till next
Network Master Idle Message. The messages generally occur
periodically and are modified slightly with a randomization term to
prevent adjacent network masters from locking and jamming each
other.
[0072] ECRC: or checksum (CRC) term is a data validation term used
to qualify the data integrity of the message for the receiver.
[0073] The network master repeatedly transmits the Network Master
Idle Message, modifying the RF Sequence number. Following
transmission of the message, the network master listens for any
slave device to send a message as depicted on timeline expansion
1003. If no slave device message is detected, the network master
resumes low power or sleep mode. The typical duty cycle for active
versus inactive is 1:1000. The precise duty cycle is a tradeoff
between response time for a slave device and battery live of the
master device.
[0074] A slave device monitors the idle messages of the network
master. When it needs to communicate to the master, it will respond
in the time window immediately following the master idle message as
shown in 1003. Optionally, in one embodiment of the present
invention there is a subsequent acknowledgement from the master to
the slave immediately following the slave response. If implemented,
this acknowledgement confirms the message was received by the
master device.
[0075] The network slave device transmits data to the network
master using a Network Slave Response Message 1005 protocol. This
message contains one or more of the following data terms:
[0076] LEADER: data term used by the receiving device (network
master) to detect a message start.
[0077] MASTER ID: a repeat of the master ID received. This is the
electronic serial number (ESN) of the master asset management
device.
[0078] SLAVE ID: data term specific and unique to a network slave
device. This is the electronic serial number (ESN) of the slave
device.
[0079] CONTROL REGISTER: contains a set of data terms used to
manage the local network. The Network Slave Response Message
Control Register 1204 is further described in FIG. 12, where the
specific terms include one or more of the following:
[0080] CNTRL/TX: a term instructing the network master to relay the
information in a subsequent transmission to the data satellite
network or short-range transceiver interface. This term is set to
no-transmit for supervisory and data log type messages.
[0081] CNTRL/DEV TYPE: a term denoting the device type acting as a
network slave.
[0082] CNTRL/GPS: a term that instructs the network master to
perform a GPS function, and/or pass payload verbatim, and/or then
replace a specific field of data in the payload with location data
prior to transmission or data store.
[0083] CNTRL/D: a term instructing the network master to store data
for collection by an external network controller such as a repeater
or gateway device.
[0084] RF Sequence Number: a term that enumerates the specific time
window allocated to the Network Master Idle Message. The network
master increments this sequence number between 0 to 31 and then
repeats the sequence one or more times. The range of sequence
numbers is not critical to the operation of the method. 32
individual time slots were chosen for the present embodiment to
facilitate up to 32 different slave devices per network master.
Each Slave device may seize an available RF sequence number Time
Division Multiple Access (TDMA) slot for responding to the master
idle message and predominately use this slot for all communications
to the network master, or alternatively simply attempt
communication on any time receive window of the master device. The
method for timeslot selection can be established during Slave setup
mode.
[0085] Payload: a term that contains sensor or remote slave data to
be acted upon by the network master. The payload field is further
defined for use in the asset management device to include specific
sensor types, data logging functions, data relay, and location
determination commands.
[0086] CRC: or Cyclic Redundancy Checksum (CRC) term is a data
validation term used to qualify the data integrity of the message
for the receiver.
[0087] Two types of slave devices are supported, bound or unbound.
Additionally, a slave device can operate in one of three modes,
acquire, track, and alarm. In acquire mode, the slave device
listens for all Network Master Idle Messages observable.
[0088] If a bound sensor in acquire mode detects and decodes the
message, it will confirm that the Master ID matches the master ID
configured in the sensor, and thus the sensor has found the master
it is logically bound with. If the Master ID does not match the
configured term, it ignores the message and continues monitoring
additional messages. Upon detection of the appropriate Network
Master Idle Message, the slave will transmit to the network master
with a Network Slave Response Message 1005 time coincident to the
network master listen interval. The slave device can then
transition from acquire mode to track mode. The network master may
optionally be configured to engage a function upon determination of
a lost sensor or slave device that fails to report in a specified
period of time. For example, the network master may send a data
message to the satellite data network notifying the detection of a
lost sensor. This enables a security notification for a locally
disabled sensor such as a door switch.
[0089] In track mode, the sensor will resume a low power state
coincident with the master low power state and awaken each master
sync message to track and stay in sync with the network master. The
slave need not transmit each wake interval, but merely track to
follow the randomized Dither parameters. If the slave misses a sync
message, it merely resumes acquire mode. The slave will
periodically transmit a supervisory message to the network master
to keep the master from timing out and transmitting a lost sensor
message, if the function is enabled.
[0090] If a sensor determines it is time to perform the designed
function, such as detection of an door open, a temperature alarm,
or a wired input alarm, the sensor will engage alarm mode. In this
mode the sensor will initiate a Network Slave Response Message on
the next TDMA window coincident with the RF Sequence number
detected when the unit engaged tracking mode, or alternatively
simply transmit in the receive time window following any master
idle message.
[0091] An unbound sensor operates as a bound sensor except that it
will engage any network master available, ignoring the Master ID
field match that the bound sensor performs. Unbound sensors operate
as slave devices that can relay sensor data through any conduit
available, generally with the purpose of relaying to the satellite
data network the sensor data independent of the asset management
device used. Examples of use for unbound sensors include cargo
tags, security switches, industrial data sensors etc. In each of
these cases, the sensor data itself is the valuable item, and the
asset management device used to relay this data is relatively
unimportant. The data may be relayed to the satellite data network
or a local recipient via the short-range transceiver interface.
Additionally, the data may be logged to local data storage 311 of
the asset management device.
[0092] A sensor may remain in track mode until it is time to
perform a transmit function and then wait until the desired RF
Sequence number occurs, or it may remain totally dormant, then
engage acquire mode to initiate a data transmission. If a sensor is
logging or monitoring data or is monitored by the system for a lost
sensor, it is usually configured to remain in track mode,
generating periodic supervisory messages to the network master. If
a sensor is very infrequently used, it is probably dormant, and
will acquire only upon sensor event. In this case the acquisition
cycle would appear as depicted in the embodiment of FIG. 11.
[0093] When the sensor event occurs coincident to 1103 in the
diagram, the sensor engages listen mode waiting to hear the next
master idle message 1101 with an embedded RF sequence number (4 in
the case of the diagram). Decoding the transmitted master idle
message, the sensor may notice another sensor transmitting in the
slot or simply not successfully complete the communication link
through active acknowledgement on the Slave Response fail. The
sensor may reschedule a second attempt, noting the DITHER term,
denoting the next event window and resuming low power mode to
awaken at the end of the sleep interval. On waking, the sensor may
again fail to finish the communication exchange as depicted, and
again reschedule for the next time window. The sensor would
continue this process until it successfully communicates 1104 with
the network master with the successful slave response message
1105.
[0094] A similar approach is used for sensors that are experiencing
difficulty in reliably communicating as determined by a CRC test.
The sensor would simply track to the next available slot and
operate within that TDMA sequence number slot. In this way, high
densities of sensors and masters will dynamically adjust to operate
correctly, with the network master merely monitoring and collecting
data. The network master sets up the structure for sensors to
adjust and collects data from any TDMA slot without priority or
weight of position. This pushes down the network management to
sensors that are equipped with a mechanism to automatically adjust
and acquire communication channels of the master.
[0095] Data security remains a concern over any communication link,
especially wireless links. The short-range transceiver interface
can incorporate three levels of encryption in the master idle
messages 1004 and the network slave response messages 1005. The
encryption is designed to allow for friendly (owner devices) and
foreign (other party's devices) cooperation without enabling misuse
of the communication link.
[0096] The lowest level of encryption is disabled. Disabled
encryption allows for any person to observe, configure, or copy the
communication of a given local network. A network operating without
encryption allows for any sensor to operate over any network
manager in bound or unbound modes.
[0097] The next level of encryption is moderate. Moderate
encryption, as depicted in 1004, uses an encryption key that
scrambles the data following the leader. The encryption key is
generally provided to a given user of the network hardware. All
master and slave devices will use the same key allowing all devices
of a given user (friendly) to operate together and ignore any other
similar devices (foreign) of another party. This prevents unbound
sensors of a user from using a foreign master to relay data over
the data satellite network (and also the battery usage associated
with the master function). Moderate encryption allows for the
detection of communication in a local region but not the
interpretation of the communication. The CRC checksum could be
redundantly encrypted (ECRC) as shown in 1004 or un-encrypted (CRC)
as shown in 1005.
[0098] The last level of encryption is high. High encryption
scrambles all the data of the message including the leader. As with
moderate encryption, only friendly devices have access to the
communication network. But unlike moderate encryption, high
encryption mode makes it impossible for a foreign observer to
detect or intercept communications in a local region. Without the
encryption key, the operation of the network is undetectable.
[0099] The short-range transceiver interface as described above is
also suitable for use with other slave devices such as
configuration tools, data logging interfaces, gateway, and repeater
devices. Configuration tools can initiate a communication link with
a master device by connecting as a slave device and then passing a
payload command that engages configuration mode. Similarly,
configuration tools can initiate a communication link with a slave
device by connecting as a master device with a pre-defined master
ID of a configuration tool. Slave devices within range of the
configuration tool would receive the configuration master idle
message and abort following any previously bound network master and
rebind to the configuration tool. The tool then communicates the
desired configuration changes and releases the slave to resume
operation with the specified network master.
[0100] Gateway devices can similarly connect to master and slave
devices within range of the short-range transceiver link. The
embodiment of FIG. 13 depicts the operation of gateways and
repeaters retrieving data from a network master. Line 1301
represents a time line for a sensor or slave device connected or
bound to a local network master 1302. As described above, the slave
device listens to the network master 1305 awaiting his RF Sequence
TDMA window to pass sensor data to the master. Once the slave
decodes the desired RF Sequence number 1306, it responds to the
master with a slave response message 1307. The slave response
message may command the network master (as a term in the payload
field) to send the payload to the data satellite network,
short-range transceiver network, store in data storage, or any
combination thereof. If the master contains any data in data
storage, it sets the CNTRL/S term 1202 which is transmitted in each
subsequent master idle message. This is denoted as a solid
rectangle on the master timelines of FIG. 13.
[0101] Operating as slave devices, a gateway device can link to any
network master and effect configuration changes and pass and
collect data. Operating as a network master, the gateway device can
connect to a slave device and effect configuration changes and pass
and collect data.
[0102] A repeater is a gateway device that connects to a local
network master to relay data from that network to a nearby gateway
using a short-range transceiver interface. Time line 1303
represents the operation of a repeater in collecting data from a
local network master. The repeater device monitors the master idle
messages 1308 and notes the presence of the CNTRL/S flag 1309
indicating the master is holding data that can be collected. The
repeater device then delays a randomized time interval 1310 and
initiates a dialog with the network master by issuing a slave
response message 1311 with the Type field of the Control Register
denoting Transparent Modem. The network master and repeater device
engage a point-to-point communications link 1312 where the gateway
retrieves the held information, clearing the CNTRL/S flag of the
network master. The network master resumes sending periodic idle
messages 1313 with the CNTRL/S flag cleared.
[0103] The repeater then changes modes and becomes a new local
network master 1314, transmitting the Idle message with a CNTRL/S
flag set. The repeaters also incorporate use of the Repeat Level
term to either bit-mask by installed repeater instance or by
incrementing count to ensure the message will not be repeated
indefinitely. Subsequent repeaters or gateways, can pull the data
from the repeater operating as a master. In this way, slave
response messages stored in a local network masters may propagate
through repeaters to distant gateway devices for collection.
[0104] A gateway monitors all network masters 1304, including the
repeater operating in slave mode. Upon the detection of a CNTRL/S
bit in either a network master or a repeater 1314, the gateway will
delay a random time interval 1315 before responding with a slave
response message 1316 to engage transparent modem mode and retrieve
the data 1317. Once the data has been retrieved from a repeater, it
will resume slave mode 1319, again searching for data to
retrieve.
[0105] Similarly, a local network master may perform the logical
functions of a repeater by alternating as a master and a slave to
another nearby master. In this mode of operation, a group of
network masters may collectively network to build a bridge for
local sensor and other master data to hand off data to a regionally
configured gateway or fixed repeater.
[0106] In yet another embodiment of the present invention, a local
device may incorporate both master and slave operation to serve as
a local repeater to extend the range of a sensor to a local master.
This type of a device has value for sensors that are
disadvantageously placed relative to the monitoring master, such as
sensors inside metal containers with the associated master outside
the container. A single local repeater can penetrate the metal
enclosure using a master node on the inside to monitor sensors
inside the container, and using a slave node on the outside that
communicates to the local asset management master device. The local
repeater simply incorporates both communication methods to monitor
the slaves that would otherwise not be operable to the local
network master. In this case, the local repeater may use a unique
identification or it could simply mimic the identification of the
local master to the slaves.
[0107] The local network master may be configured to redundantly
store to local data storage any transmitted data satellite message,
setting the CNTRL/S term. In this way, messages that may be dropped
by the simplex satellite network are augmented through gateway
devices, often later as the device comes within range of a gateway
or repeater. The data through the gateway may be collected using a
long-range communication link and merged with data collected from
the data satellite system to create a more complete set of
data.
[0108] Similarly, gateways, repeaters, or configuration tools could
monitor the CNTRL/M and/or CNTRL/U flags to detect and retrieve
data created by the asset management device itself or remote users
who uploaded data for storage. A logistics manager may seal a
container with an asset management device affixed, then upload user
data to storage data for later retrieval at container destination.
The destination manager could monitor the idle message of the local
master and detect it by using the CNTRL/U flag if user data exists
for extraction and review.
[0109] Repeaters can retrieve data from a local network master upon
detection of a CNTRL/S flag after a random delay of several Idle
message cycle intervals. This delay allows a time window where any
local gateway will have ample opportunity to be the first to
retrieve data directly from a network master. The repeater can
randomize the Idle Sequence TDMA slot to minimize the probability
that multiple repeaters will attempt to retrieve data from a local
network master at the same Idle Sequence TDMA interval. The delays
in retrieving the data from a local network master are relatively
small compared to the standard time to resolve a GPS location
determination. Gateway devices differ from repeaters in that they
contain computation controllers, typically microprocessor based and
custom algorithms and software to perform a variety of
functions.
[0110] The ability of embodiments of the present invention to
establish private or public networks to control battery powered
remote simplex asset management devices is unique. Other two-way
type devices do not incorporate a wireless architecture that will
support battery operation, let alone provide for the additional
capability of supporting wireless sensors. The present invention
discussed herein provides utility in container security, rail,
marine, fixed and mobile security, trailer tracking and more on a
global scale, operable using batteries for years of service.
[0111] Many of the algorithmic operations and functions described
herein may be implemented using a conventional general purpose
computer or microprocessor programmed according to the teachings of
the present invention, as will be apparent to those skilled in the
art. Appropriate software can readily be prepared by programmers of
ordinary skill based on the teachings of the present disclosure as
will be apparent to those skilled in the art.
[0112] A general-purpose computer may be used to implement the
method of the present invention, wherein the computer housing
houses a motherboard which contains a CPU, memory (e.g., DRAM, ROM,
EPROM, EEPROM, SRAM, SDRAM, and Flash RAM), and other optional
special purpose logic devices (e.g., ASICS) or configurable logic
devices (e.g., GAL and reprogrammable FPGA). The computer also
includes plural input devices, (e.g., keyboard and mouse), and a
display card for controlling a monitor. Additionally, the computer
may include a floppy disk drive; other removable media devices
(e.g. compact disc, tape, and removable magneto optical media); and
a hard disk or other fixed high density media drives, connected
using an appropriate device bus (e.g., a SCSI bus, an Enhanced IDE
bus, or an Ultra DMA bus). The computer may also include a compact
disc reader, a compact disc reader/writer unit, or a compact disc
jukebox, which may be connected to the same device bus or to
another device bus.
[0113] As stated above, the system includes at least one computer
readable medium.
[0114] Examples of computer readable media are compact discs, hard
disks, floppy disks, tape, magneto optical disks, PROMs (e.g.,
EPROM, EEPROM, Flash EPROM), DRAM, SRAM, SDRAM, etc. Stored on any
one or on a combination of computer readable media, the present
invention includes software for controlling both the hardware of
the computer and for enabling the computer to interact with a human
user. Such software may include, but is not limited to, device
drivers, operating systems and user applications, such as
development tools. Computer program products of the present
invention include any computer readable medium which stores
computer program instructions (e.g., computer code devices) which
when executed by a computer causes the computer to perform the
method of the present invention. The computer code devices of the
present invention can be any interpretable or executable code
mechanism, including but not limited to, scripts, interpreters,
dynamic link libraries, Java classes, and complete executable
programs. Moreover, parts of the processing of the present
invention may be distributed (e.g., between (1) multiple CPUs or
(2) at least one CPU and at least one configurable logic device)
for better performance, reliability, and/or cost.
[0115] The invention may also be implemented by the preparation of
application specific integrated circuits or by interconnecting an
appropriate network of conventional component circuits, as will be
readily apparent to those skilled in the art. Numerous
modifications and variations of the present invention are possible
in light of the above teachings. It is therefore to be understood
that within the scope of the appended claims, the invention may be
practiced otherwise than as specifically described herein.
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