U.S. patent application number 15/590880 was filed with the patent office on 2017-08-24 for determining presence of a radio frequency communication device.
This patent application is currently assigned to Google Inc.. The applicant listed for this patent is Google Inc.. Invention is credited to Khanh Mai, Robert W. Twitchell, JR..
Application Number | 20170245215 15/590880 |
Document ID | / |
Family ID | 40641861 |
Filed Date | 2017-08-24 |
United States Patent
Application |
20170245215 |
Kind Code |
A1 |
Twitchell, JR.; Robert W. ;
et al. |
August 24, 2017 |
Determining Presence of a Radio Frequency Communication Device
Abstract
A radio communication device includes a two-way communications
component having a first receiver and transmitter, an interface for
receiving one or more sensor signals based on sensor-acquired data
that is indicative of a predetermined condition, electronic
components, and a second receiver. The second receiver activates
the two-way communications component from a dormant state upon
receipt by the second receiver of a wake-up broadcast that includes
a wake-up identifier of the data communication device. The wake-up
broadcast includes a data construct including a wake-up identifier
and the auxiliary information. The auxiliary information is
received and recorded by the data communication device via the
second receiver with the two-way communications component remaining
in the dormant state. The device operates in two states, the device
enters a first state from a second state upon receiving one or more
sensor signals based on sensor-acquired data that is indicative of
a predetermined condition.
Inventors: |
Twitchell, JR.; Robert W.;
(Cummings, GA) ; Mai; Khanh; (Alpharetta,
GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Google Inc. |
Mountain View |
CA |
US |
|
|
Assignee: |
Google Inc.
Mountain View
CA
|
Family ID: |
40641861 |
Appl. No.: |
15/590880 |
Filed: |
May 9, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15052172 |
Feb 24, 2016 |
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15590880 |
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13555897 |
Jul 23, 2012 |
9295099 |
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15052172 |
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12353197 |
Jan 13, 2009 |
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13555897 |
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PCT/US2008/054630 |
Feb 21, 2008 |
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12353197 |
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11618931 |
Jan 1, 2007 |
7907941 |
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15052172 |
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60891008 |
Feb 21, 2007 |
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60766223 |
Jan 1, 2006 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 12/0017 20190101;
H04W 52/0235 20130101; H04W 12/04 20130101; Y02D 70/146 20180101;
Y02D 70/142 20180101; Y02D 70/162 20180101; Y02D 70/144 20180101;
Y02D 70/164 20180101; H04W 84/18 20130101; H04L 67/145 20130101;
Y02D 70/22 20180101; Y02D 30/70 20200801; Y02D 70/23 20180101 |
International
Class: |
H04W 52/02 20060101
H04W052/02; H04L 29/08 20060101 H04L029/08; H04W 12/04 20060101
H04W012/04 |
Claims
1. A wireless communication device, comprising: a radio receiver
configured to receive a radio transmission as data representative
of a general inquiry as to the presence of wireless communication
devices; a radio transmitter configured to respond to the received
radio transmission with an identifier associated with the wireless
communication device, the wireless communication device configured
to enter a low-power state in which the wireless communication
device does not respond to additional radio transmissions that
include the data representative of the general inquiry as to the
presence of wireless communication devices; and an interface for
receiving one or more signals from a sensor, the interface
configured to: receive a sensor signal based on sensor-acquired
data that is indicative of a predetermined condition; and in
response to the reception of the sensor signal, exit the low-power
state and transmit an additional radio transmission that includes
the identifier associated with the wireless communication
device.
2. The wireless communication device of claim 1, comprising a
timer, and wherein the wireless communication device is configured
to use the timer as an indication of when to transmit at periodic
intervals.
3. The wireless communication device of claim 1, wherein the sensor
is a motion sensor.
4. The wireless communication device of claim 1, wherein the sensor
is a temperature sensor.
5. The wireless communication device of claim 1, wherein the sensor
is a GPS receiver.
6. The wireless communication device of claim 5, wherein the
predetermined condition comprises movement of the wireless
communication device as determined by the GPS receiver.
7. The wireless communication device of claim 6, wherein the
determined movement of the wireless communication device is based
on the sensor-acquired data exceeding a threshold based on a
comparison of the sensor-acquired data to a geofence.
8. The wireless communication device of claim 1, wherein the
predetermined condition is one or more of: a change in temperature,
a change in location, or movement of the wireless communication
device.
9. The wireless communication device of claim 1, further comprising
a housing and wherein the sensor is internal to the housing of the
wireless communication device.
10. The wireless communication device of claim 1, further
comprising a housing and wherein the sensor is external to the
housing of the wireless communication device.
11. The wireless communication device of claim 1, wherein the
wireless communication device comprises one or more additional
interfaces configured to receive additional signals from one or
more additional sensors.
12. The wireless communication device of claim 11, wherein the
predetermined condition is based on the additional signals from
multiple sensors of the one or more additional sensors.
13. A wireless sensor network system comprising: a gateway node
configured to transmit a radio packet that includes data
representative of a general inquiry as to the presence of wireless
network nodes; a wireless network node configured to: receive the
radio packet that includes the data representative of the general
inquiry as to the presence of the wireless network nodes; respond
to the received packet by transmission of a response radio packet
that includes an identifier associated with the wireless network
node; enter a low-power state in which the wireless network node
does not respond to additional radio packets that include the data
representative of the general inquiry as to the presence of
wireless network nodes; receive a sensor signal, via an interface,
based on sensor-acquired data that is indicative of a predetermined
condition; and in response to the reception of the sensor signal
exit the low-power state and transmit an additional radio packet
that includes the identifier associated with the wireless network
node.
14. The wireless sensor network system of claim 13, wherein the
gateway node is configured to: receive the response radio packet;
and receive the additional radio packet.
15. The wireless sensor network system of claim 13, wherein the
sensor signal is received from a sensor configured as one of: a
motion sensor, a temperature sensor, or a GPS receiver.
16. The wireless sensor network system of claim 13, wherein the
wireless network node comprises a timer, and wherein the wireless
network node is configured to use the timer as an indication of
when to transmit at periodic intervals.
17. The wireless sensor network system of claim 13, wherein the
predetermined condition is one or more of: a change in temperature,
a change in location, or movement of the wireless network node.
18. A method of reporting the presence of a communication device in
a wireless network, the method comprising: receiving, by the
communication device while the communication device is in a first
state, a radio transmission that includes data representative of a
general inquiry as to the presence of communication devices;
responding to the received radio transmission by generating a radio
transmission that includes an identifier associated with the
communication device; entering a second state in which the
communication device does not respond to additional radio
transmissions that include the data representative of the general
inquiry as to the presence of communication devices; receiving, via
an interface, a sensor signal based on sensor-acquired data that is
indicative of a predetermined condition; returning to the first
state in response to the receiving the sensor signal; and
transmitting an additional radio transmission that includes the
identifier associated with the wireless communication device.
19. The method of claim 18, wherein the sensor signal is received
from a sensor configured as one of: a motion sensor, a temperature
sensor, or a GPS receiver.
20. The method of claim 18, wherein the predetermined condition is
one or more of: a change in temperature, a change in location, or
movement of the communication device.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a U.S. continuation patent
application of, and claims priority under 35 U.S.C. .sctn.120 to,
U.S. nonprovisional patent application Ser. No. 15/052,172, filed
Feb. 24, 2016, which published as U.S. Patent Application
Publication No. 2016/0219523, which is a U.S. continuation patent
application of, and claims priority under 35 U.S.C. .sctn.120 to,
U.S. nonprovisional patent application Ser. No. 13/555,897, filed
Jul. 23, 2012, which published as U.S. Patent Application
Publication No. 2013/0223420, which is a U.S. continuation patent
application of, and claims priority under 35 U.S.C. .sctn.120 to,
Ser. No. 12/353,197, filed Jan. 13, 2009, which published as U.S.
Patent Application Publication No. 2009/0129306, which is a U.S.
continuation patent application of, and claims priority under 35
U.S.C. .sctn.120 to, international patent application serial number
PCT/US2008/054630 filed on Feb. 21, 2008, and designating the
United States, which published as WO2008/103861 on Aug. 28, 2008,
and claims priority under 35 U.S.C. .sctn.119(e) to, U.S.
provisional patent application Ser. No. 60/891,008, filed Feb. 21,
2007. The present patent application also claims priority under the
Paris Convention to U.S. Patent Application Ser. No. 60/766,223,
filed Jan. 1, 2006. For purposes of the United States, the present
patent application further is a U.S. continuation patent
application of, and claims priority under 35 U.S.C. .sctn.120 to,
U.S. nonprovisional patent application Ser. No. 11/618,931, filed
Jan. 1, 2007, which published as U.S. Patent Application
Publication No. 2007/0155327, and claims priority under 35 U.S.C.
.sctn.119(e) to, U.S. Patent Application Ser. No. 60/766,223, filed
Jan. 1, 2006 Each of these patent applications and patent
application publications are hereby incorporated herein by
reference.
[0002] The present application incorporates herein by reference
each of the following patent application publications and patents,
each of which is owned by the assignee of the present application:
U.S. Pat. No. 7,209,771, U.S. Pat. No. 7,221,668, U.S. Pat. No.
7,155,264, U.S. Pat. No. 7,133,704, U.S. Pat. No. 6,934,540, U.S.
Pat. No. 6,745,027, U.S. Patent Application Publication No. US
2006/0018274, U.S. Patent Application Publication No. US
2005/0215280, U.S. Patent Application Publication No. US
2006/0023679, U.S. Patent Application Publication No. US
2006/0023678, U.S. Patent Application Publication No. US
2006/0023678, U.S. Patent Application Publication No. US
2006/0023679, U.S. Patent Application Publication No. US
2006/0237490, U.S. Patent Application Publication No. US
2006/0276963, U.S. Patent Application Publication No. US
2006/0282217, U.S. Patent Application Publication No. US
2006/0276161, U.S. Patent Application Publication No. US
2006/0289204, U.S. Patent Application Publication No. US
2006/0274698, U.S. Patent Application Publication No. US
2006/0287822, U.S. Patent Application Publication No. US
2006/0287008, U.S. Patent Application Publication No. 2007/0002792,
and U.S. Patent Application Publication No. 2007/0155327.
COPYRIGHT STATEMENT
[0003] All of the material in this patent document is subject to
copyright protection under the copyright laws of the United States
and other countries. The copyright owner has no objection to the
facsimile reproduction by anyone of the patent document or the
patent disclosure, as it appears in official governmental records
but, otherwise, all other copyright rights whatsoever are
reserved.
BACKGROUND
[0004] Wireless ad hoc networks comprise nodes that communicate
without central control or wired infrastructure. Such networks may
have dynamic, randomly-changing, multihop topologies composed of
wireless data communication links between the nodes. Ad hoc
networks are advantageous because they are inexpensive,
fault-tolerant, and flexible.
[0005] The present invention relates to improvements in wireless ad
hoc networks and, in particular, improvements in such networks that
utilize common designation networking.
[0006] In another aspect, conventional systems for tracking and/or
monitoring assets (herein generally referred to as "asset tracking
systems") utilize wireless tags that generally respond to any
broadcast that is made. The wireless tags usually are passive, and
the responses that the passive wireless tags make are often
referred to as "chirps."
[0007] More sophisticated asset tracking systems utilize
semi-passive wireless tags and/or active wireless tags. A
semi-passive wireless tag includes an internal power source for
transmitting, and an active wireless tag includes an internal power
source for both receiving and transmitting. Semi-passive and active
wireless tags generally have greater capabilities than passive
wireless tags due to the internal power sources. Of course, power
consumption is always a concern when a wireless tag includes an
internal power source, since the internal power supply limits the
useful life of the wireless tag, after which time maintenance is
required (e.g., replacement of the internal power source).
[0008] In improved asset tracking systems, such as those disclosed
in the above patent applications and patents that have been
incorporated herein by reference, a wireless tag responds to a
broadcast if the broadcast includes a common designation matching a
common designation of the wireless tag. Such a common designation
may comprise, for example, an "asset class" associated with the
wireless tag. Ad hoc networks further may be created based on such
classes, which ad hoc networks are referred to as "class based"
networks.
[0009] Class based networks (and common designation networks in
general) are beneficial because, in such networks, a communication
device, such as a wireless tag, generally only transmits a response
to a broadcast if the broadcast includes a class (or common
designation) that matches a class (or common designation) of that
communication device. Indeed, in a communication device employing a
wakeup sequence of one or more of the patent references
incorporated herein by reference, such communication device does
not even process a broadcast once it is determined that the
broadcast fails to include a matching class of the communication
device. Consequently, the internal power supply of a semi-passive
or active communication device is not drained by needless
processing and/or responses to broadcasts.
[0010] In asset tracking systems, it often is important to know the
physical location of an asset. This could include knowing where the
asset is within a limited physical area, such as a warehouse; this
also could include knowing where the asset is within several
different warehouses in several different geographical locations,
as well as where the asset is during transit between such
locations.
[0011] In a conventional asset tracking system in which
communication devices comprising semi-passive or active radios are
placed on the assets, a conventional method for acquiring
visibility of the assets includes broadcasting within an area at
regular intervals to solicit responses from all of the radios
within the area. The responses from the radios reveal the radios,
and thus the assets, that are in the area.
[0012] This method is not advantageous because the regular,
repetitive broadcasts result in an unnecessary power drain of the
responding radios. Interference also can occur if a large number of
radios respond at the same time, thereby making it difficult to
accurately identify all of the radios within the area that respond
to the broadcast.
[0013] In an alternative conventional method, a timer is included
with each radio and the radio is configured to transmit at periodic
intervals as a function of the timer. The radio thereby alerts the
tracking system as to the whereabouts of the radio and, thus, the
asset with which it is associated. By including timers with each
radio, the radios may transmit at differing times in order to avoid
unnecessary interference. A radio also can be set to sleep between
intervals and to be awoken by the timer for making its regular
transmissions. This increases the useful life of the radios because
the radios do not consume power by actively listening for
broadcasts while sleeping.
[0014] This alternative method permits determinations as to the
delivery and continued presence of an asset at a particular area.
Nevertheless, this alternative method does include drawbacks. For
instance, by using timers, the radios are inaccessible by the asset
tracking system during the sleep periods. Another drawback is that
the radios automatically awake and transmit without regard for
their location and without regard for whether the transmission is
actually warranted or even desired. In this respect, during
transportation on a plane, a radio may awaken and transmit, which
may cause unwanted interference with the operation of the airplane.
Preprogrammed transmission at regular intervals also may reveal the
presence of the asset to unauthorized persons snooping for such
radio transmissions.
[0015] Accordingly, better asset tracking systems and methods are
desired that minimize unnecessary power consumption and that reduce
unnecessary transmissions by communication devices associated with
assets.
SUMMARY
[0016] The present invention broadly relates to improved common
designation networking and common designation networks and, in
particular, to wireless communications utilizing improved common
designation networking and common designation networks within
wireless ad hoc networking environments.
[0017] Broadly described, the present invention includes many
aspects and features.
[0018] The invention relates to ad hoc wireless networking
utilizing a data communication device as a node of the network,
wherein the data communication device includes both a two-way
communications component comprising a first receiver and
transmitter, and a second receiver, and wherein the second receiver
activates the two-way communications component from a dormant state
upon receipt by the second receiver of a wake-up broadcast that
includes a wake-up identifier of the data communication device.
[0019] In accordance with an aspect of the invention, a method of
providing information via the second receiver-which information is
auxiliary to the wake-up of the two-way data communications
component-includes transmitting a wake-up broadcast. The wake-up
broadcast is capable of being received by the second receiver if in
broadcast range, and the wake-up broadcast includes a data
construct comprising a wake-up identifier and the auxiliary
information. The wake-up identifier may or may not be the wake-up
identifier of the data communication device. Nevertheless, the
auxiliary information is received and recorded by the data
communication device via the second receiver with the two-way
communications component remaining in the dormant state.
[0020] In another aspect of the invention, a method of receiving
information by the data communication device via the second
receiver-which information is auxiliary to the wake-up of two-way
communications component-includes the steps of: receiving a wake-up
broadcast, the wake-up broadcast including a data construct
comprising a wake-up identifier and the auxiliary information;
storing the auxiliary information in memory of the data
communication device; and activating the two-way communications
component from a dormant state, in response to receipt of the
wake-up broadcast, if a wake-up identifier of the data
communications device is found in the wake-up broadcast, and not
activating the two-way communications component from a dormant
state, in response to receipt of the wake-up broadcast, if a
wake-up identifier of the data communications device is not found
in the wake-up broadcast.
[0021] In features of these aspects, the auxiliary information
comprises a node identification from which the wake-up broadcast is
transmitted; the auxiliary information comprises a transmission
count regarding wake-up broadcasts transmitted by a node; the
auxiliary information comprises an encryption key; the auxiliary
information comprises application specific data; and/or the
auxiliary information comprises an indication of the status of a
sensor.
[0022] In additional features, the second receiver draws
substantially less current while listening for a wake-up broadcast
than the two-way communications component would draw while
listening for a wake-up broadcast; the second receiver draws less
current while listening for a wake-up broadcast than the two-way
communications component would draw while listening for a wake-up
broadcast, the difference in current draw being at least an order
of magnitude (such as milliamps versus microamps); and/or the
second receiver utilizes a stepped wake-up sequence based on at
least two criteria, and wherein the last criteria before awakening
the two-way communications component comprises identifying a
wake-up identifier of the data communication device in the wake-up
broadcast.
[0023] In another feature, of these aspects, the second receiver is
part of a wake-up transceiver, and the wake-up transceiver further
comprises a second transmitter of the data communication device
that is configured to transmit a wake-up broadcast for receipt by
another wake-up receiver of another data communication device.
[0024] In various implementations of these aspects, the data
communication device is a node in a common designation wireless ad
hoc sensor network; and/or the data communication device is a node
in a class based wireless ad hoc network.
[0025] In yet additional features of these aspects, the auxiliary
information is used by the data communication device for
facilitating network communications by the two-way communications
component. In this regard, the auxiliary information may include
network information that is reviewed by the data communication
device when determining network paths for communicating with a
desired node, whereby network communications are facilitated. The
network information may include: the identification of one or more
nodes that are within direct communication range of the data
communication device; the identification of a gateway node that is
within direct communication range of the data communication device;
the identification of one or more nodes from which wake-up
broadcasts have been received, either directly or indirectly, by
the second wake-up receiver; and/or the identification of one or
more common designations from which wake-up broadcasts have been
received, either directly or indirectly, by the second wake-up
receiver.
[0026] Another aspect of the invention includes computer executable
instructions stored in a computer readable medium for performing
any of the foregoing aspects and features, including any
combinations thereof.
[0027] In yet another aspect of the invention, an ad hoc wireless
network system includes an ad hoc wireless network utilizing a
plurality of data communication devices as nodes of the network;
wherein each data communication device includes both a two-way
communications component, comprising a first receiver and
transmitter, and a second receiver, wherein the second receiver
activates the two-way communications component from a dormant state
upon receipt by the second receiver of a wake-up broadcast that
includes a wake-up identifier of the data communication device; and
wherein information is provided via each second receiver, which
information is auxiliary to the wake-up of the two-way
communications component, by transmitting a wake-up broadcast,
which the second receiver is capable of receiving, that includes a
data construct comprising a wake-up identifier and the auxiliary
information.
[0028] In still another aspect of the invention, a data
communication device for utilization as a node in an ad hoc
wireless network includes a two-way communications component
comprising a first receiver and transmitter; and a second receiver,
wherein the second receiver activates the two-way communications
component from a dormant state upon receipt by the second receiver
of a wake-up broadcast that includes a wake-up identifier of the
data communication device; wherein information is provided via the
second receiver, which information is auxiliary to the wake-up of
the two-way communications component, by transmitting a wake-up
broadcast, which the second receiver is capable of receiving, that
includes a data construct comprising a wake-up identifier and the
auxiliary information.
[0029] Additional aspects and features relate to, and are described
in, the context of asset tracking systems, the present invention is
not limited to use only in asset tracking systems, as will become
apparent from the following summaries and detailed descriptions of
aspects, features, and one or more embodiments of the present
invention. For instance, one or more aspects of the present
invention may be utilized to determine the presence or arrival of a
communication device within an area independent of any asset and/or
independent of any asset tracking system. The present invention
also is not limited to use in common designation or class-based
networks, although in preferred embodiments common designation or
class-based networks are used. Indeed, the present application may
beneficially be used in asset tracking as well as sensor
monitoring, hazmat monitoring, first responder scenarios, military
activities and situations, mobile phone applications, and
automobile dealer key tracking systems.
[0030] Accordingly, an aspect of the present invention relates to a
radio frequency communication device that includes a receiver
configured to receive radio frequency transmissions; a transmitter
configured to make radio frequency transmissions; an interface for
receiving a signal from a sensor (hereinafter "sensor signal"); and
electronic components. In accordance with this aspect of the
invention, the electronic components are arranged and configured
such that the radio frequency communication device operates in at
least two states.
[0031] In the first state, the radio frequency communication device
responds to a radio frequency transmission that is received by the
receiver and that includes data representative of an inquiry as to
the presence of radio frequency communication devices within an
area. The "data representative of an inquiry as to the presence of
radio frequency communication devices within an area" simply may be
a predefined value in a particular format within the broadcast in
accordance with a predefined protocol. A radio frequency
transmission that includes such data is sometimes referred to
herein as a "Present Broadcast." The response to the Present
Broadcast is made by the radio frequency communication device by
making a radio frequency transmission with the transmitter that
includes an identification of the radio frequency communication
device. A radio frequency transmission that includes an
identification of the radio frequency communication device making
the transmission, and that is made in response to a Present
Broadcast, is sometimes referred to herein as a "Present
Response."
[0032] In the second state, the radio frequency communication
device does not respond to a Present Broadcast with a Present
Response; specifically, no response to a Present Broadcast
comprising a radio frequency transmission is made with the
transmitter that includes an identification of the radio frequency
communication device, and preferably, no response to a Present
Broadcast comprising a radio frequency transmission is made at all,
whether including an identification of the radio frequency
communication device or otherwise.
[0033] In further accordance with this aspect of the invention, the
electronic components are arranged and configured such that the
radio frequency communication device enters the second state from
the first state upon responding to a Present Broadcast with a
Present Response. The electronic components further are arranged
and configured such that the radio frequency communication device
enters the first state from the second state upon receiving,
through the interface, a sensor signal based on sensor-acquired
data that is indicative of a predetermined condition. The sensor
signal itself may include the sensor-acquired data or may be
representative of the sensor-acquired data and may indicate, for
example, a state of the sensor. In any event, such sensor signal is
deemed to provide "sensor-acquired information" through the
interface.
[0034] In a feature of this aspect, the first and second states
relate only to whether the communication device responds to a
Present Broadcast. Thus, the communication device otherwise remains
responsive to other broadcasts in general and/or remains responsive
to transmissions directed to the device. For example, in
class-based networks, the communication device preferably remains
responsive to any transmission including a class to which it is a
member, whether the communication device is in the first state or
the second state. Such transmission to the communication device may
relate to a change in sensor states; maintenance of the
communication device (e.g., checking the status of the internal
power supply); or enabling or disabling of certain features or
capabilities of the communication device (including the practicing
of the present invention). In an alternative--and less
preferred--feature, the first and second states relate not only to
whether the communication device responds to a Present Broadcast,
but whether the communication device responds to any broadcast at
all. In this respect, when the communication device is in the
second state, the communication device may not respond to any
broadcasts at all.
[0035] In yet another feature of this aspect, the electronic
components are further configured such that the radio frequency
communication device makes a radio frequency transmission upon
receiving, through the interface, sensor-acquired information that
indicates a predetermined condition.
[0036] In another feature of this aspect, the radio frequency
communication device further includes a computer processor that
processes received radio frequency transmissions and received
sensor-acquired information. The computer processor preferably
effects state changes of the radio frequency communication device
as a function of received radio frequency transmissions and
received sensor-acquired information.
[0037] In still yet another feature, the communication device
enters the first state from the second state after a predetermined
period of time has transpired according to a timer of the
communication device. This feature is beneficial, for example, if a
sensor associated with a radio frequency communication device fails
and if the radio frequency communication device would not otherwise
enter the first state from the second state. In this regard, the
time period before the radio frequency communication device enters,
by default, the first state from the second state may be a
significant period of time.
[0038] In still yet another feature, the communication device
enters the first state from the second state after a predetermined
number of failed attempts to communicate with a server have
occurred. This feature is beneficial, for example, in identifying
radio frequency communication devices in a certain area that are
having technical difficulties in their communications. In still
another feature, the radio frequency communication device enters
the first state from the second state upon receipt, via the
receiver of radio frequency communication device, of an instruction
to enter the first state. The instruction may be specific to a
particular radio frequency communication device or generic to a
plurality of radio frequency communication devices. Furthermore, a
special common designation, such as a special class, may be
utilized whereby a broadcast to such common designation would
instruct radio frequency communication device having that common
designation to enter the first state. This feature is beneficial,
for example, if a sensor associated with a radio frequency
communication device fails and if the radio frequency communication
device would not otherwise enter the first state from the second
state. This enables, for example, a sever to look for a radio
frequency communication device within a particular area.
[0039] Another aspect of the invention relates to a method
performed by a radio frequency communication device. The method
includes: the first steps of responding to a Present Broadcast with
a Present Response and then not responding to any further Present
Broadcasts; and, repeating the first steps upon receiving, through
an interface of the radio frequency communication device,
sensor-acquired information that is indicative of a predetermined
condition. Thus, after receiving such sensor-acquired information,
the radio frequency communication device does, in fact, respond to
the next Present Broadcast.
[0040] In a feature of this aspect of the invention, the method
further includes the step of making a radio frequency transmission
with the transmitter of the radio frequency communication device
upon receiving, through an interface of the radio frequency
communication device, the sensor-acquired information indicative of
the predetermined condition.
[0041] In accordance with this and other aspects of the invention,
the predetermined condition may comprise movement of the radio
frequency communication device; a change, exceeding a threshold,
with respect to the location of the radio frequency communication
device as determined based on GPS data; and/or a temperature
associated with the radio frequency communication device exceeding
a predetermined threshold. With further respect to location, for
example, the data from the GPS receiver may be compared against a
range of x-y coordinates for "geo fencing" of the communication
device (e.g., 89.2412<x<89.4522 and
145.2332<y<145.8772), with a predetermined condition being
triggered by the GPS data that indicates the communication device
being outside of a predefined geographical area. An example of this
is described below with regard to FIGS. 12-19.
[0042] In further accordance with the invention, the predetermined
condition may comprise a change in state of a sensor associated
with a radio frequency communication device and the sensor may or
may not indicate movement from an area. Such a state change could
indicate, for example, the breaking of a magnetic seal or other
seal of a container wherein the sensor monitors the seal of the
container. The container could be, for example, a hazardous waste
container or an international shipping container. In such case, the
Present Broadcast could be used to reveal those containers for
which the seals have been broken.
[0043] In another feature of the invention, the radio frequency
communication device may comprises a node in one or more common
designation networks. In this respect, the data representative of a
general inquiry as to the presence of radio frequency communication
devices may be a predefined common designation. Indeed, the data
representative of a general inquiry as to the presence of radio
frequency communication devices may be a common designation of
"present."
[0044] In a related feature, the radio frequency communication
device is associated with an asset being tracked in an asset
tracking system. The asset tracking system may be a class-based
asset tracking system, and the data representative of a general
inquiry as to the presence of radio frequency communication devices
may be a predefined class designation. Indeed, the data
representative of a general inquiry as to the presence of radio
frequency communication devices may be a class designation of
"present."
[0045] It will be appreciated that, in accordance with one or more
aspects, determinations can be made as to when an asset has arrived
in an area and when an asset has left the area. Furthermore, this
can be achieved without significantly reducing battery life, and
this can be achieved without unnecessary radio frequency
transmissions.
[0046] In addition to the aforementioned aspects and features of
the invention, it should be noted that the invention further
includes the various possible combinations of such aspects and
features, including the combinations of such aspects and features
with those aspects and features of the incorporated references from
which priority is claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] Particular embodiments of the invention are to be understood
according to the detailed descriptions that follow in conjunction
with the attached figures, wherein:
[0048] FIG. 1 illustrates a plurality of nodes that form wireless
ad hoc networks in accordance with common designation networking,
wherein node N5 is sending out a wake-up broadcast to nodes having
the "circle" common designation.
[0049] FIG. 2 illustrates the nodes of FIG. 1, wherein each of
nodes N1 and N3 propagates the wake-up broadcast from node N5 and
wherein each of nodes N1 and N3 engages in Bluetooth communications
with node N5.
[0050] FIG. 3 illustrates the nodes of FIG. 1, wherein node N4
propagates the wake-up broadcast from node N5 and engages in
Bluetooth communications with node N3, and wherein node N1 engages
in Bluetooth communications with gateway G1.
[0051] FIG. 4 illustrates the nodes of FIG. 1 during a period of
inactivity of transmissions between the nodes.
[0052] FIG. 5 illustrates the nodes of FIG. 1, wherein gateway G1
sends out a wake-up broadcast targeting node N1 and engages in
Bluetooth communications with node N1.
[0053] FIG. 6 illustrates the nodes of FIG. 1, wherein node N1
sends out a wake-up broadcast targeting node N5 and engages in
Bluetooth communications with node N5.
[0054] FIG. 7 illustrates a first exemplary data construct that is
included in the wake-up broadcast in accordance with the present
invention.
[0055] FIG. 8 illustrates a second exemplary data construct that is
included in the wake-up broadcast in accordance with the present
invention.
[0056] FIG. 9 illustrates a third exemplary data construct that is
included in the wake-up broadcast in accordance with the present
invention.
[0057] FIG. 10 illustrates an exemplary table of wake-up
identifiers that may be maintained by node N2 in accordance with
the present invention.
[0058] FIG. 11 illustrates an exemplary table of wake-up
identifiers that may be maintained by gateway G 1 in accordance
with the present invention.
[0059] FIG. 12 is a first illustration representative of locations,
states, and state transitions of radio frequency communication
devices, at a first time, in accordance with one or more preferred
embodiments of the present invention.
[0060] FIG. 13 is a second illustration representative of
locations, states, and state transitions of radio frequency
communication devices, at a second time subsequent to the first
time, in accordance with one or more preferred embodiments of the
present invention.
[0061] FIG. 14 is a third illustration representative of locations,
states, and state transitions of radio frequency communication
devices, at a third time subsequent to the second time, in
accordance with one or more preferred embodiments of the present
invention.
[0062] FIG. 15 is a fourth illustration representative of
locations, states, and state transitions of radio frequency
communication devices, at a fourth time subsequent to the third
time, in accordance with one or more preferred embodiments of the
present invention.
[0063] FIG. 16 is a fifth illustration representative of locations,
states, and state transitions of radio frequency communication
devices, at a fifth time subsequent to the fourth time, in
accordance with one or more preferred embodiments of the present
invention.
[0064] FIG. 17 is a sixth illustration representative of locations,
states, and state transitions of radio frequency communication
devices, at a sixth time subsequent to the fifth time, in
accordance with one or more preferred embodiments of the present
invention.
[0065] FIG. 18 is a seventh illustration representative of
locations, states, and state transitions of radio frequency
communication devices, at a seventh time subsequent to the sixth
time, in accordance with one or more preferred embodiments of the
present invention.
[0066] FIG. 19 is an eighth illustration representative of
locations, states, and state transitions of radio frequency
communication devices, at an eighth time subsequent to the seventh
time, in accordance with one or more preferred embodiments of the
present invention.
DETAILED DESCRIPTION
[0067] As a preliminary matter, it will readily be understood by
one having ordinary skill in the relevant art ("Ordinary Artisan")
that the present invention has broad utility and application.
Various embodiments are discussed for illustrative purposes in
providing a full and enabling disclosure of the present invention.
Moreover, many embodiments, such as adaptations, variations,
modifications, and equivalent arrangements, will be implicitly
disclosed by the descriptions of embodiments herein and fall within
the scope of the present invention.
[0068] Accordingly, while the present invention is described herein
in detail in relation to one or more embodiments, it is to be
understood that this disclosure is illustrative and exemplary of
the present invention, and is made merely for the purposes of
providing a full and enabling disclosure of the present invention.
The detailed disclosure herein of one or more embodiments is not
intended, nor is to be construed, to limit the scope of patent
protection afforded the present invention. It is not intended that
the scope of patent protection afforded the present invention be
defined by reading into any claim a limitation found herein that
does not explicitly appear in the claim itself.
[0069] Thus, for example, any sequence(s) and/or temporal order of
steps of various processes or methods that are described herein are
illustrative and not restrictive. Accordingly, it should be
understood that, although steps of various processes or methods may
be shown and described as being in a sequence or temporal order,
the steps of any such processes or methods are not limited to being
carried out in any particular sequence or order, absent an
indication otherwise. Indeed, the steps in such processes or
methods generally may be carried out in various different sequences
and orders while still falling within the scope of the present
invention. Accordingly, it is intended that the scope of patent
protection afforded the present invention is to be defined by the
appended claims rather than the description set forth herein.
[0070] Additionally, it is important to note that each term used
herein refers to that which the Ordinary Artisan would understand
such term to mean based on the contextual use of such term herein.
To the extent that the meaning of a term used herein--as understood
by the Ordinary Artisan based on the contextual use of such
term--differs in any way from any particular dictionary definition
of such term, it is intended that the meaning of the term as
understood by the Ordinary Artisan should prevail.
[0071] Furthermore, it is important to note that, as used herein,
"a" and "an" each generally denotes "at least one," but does not
exclude a plurality unless the contextual use dictates otherwise.
Thus, reference to "a picnic basket having an apple" describes "a
picnic basket having at least one apple" as well as "a picnic
basket having apples." In contrast, reference to "a picnic basket
having a single apple" describes "a picnic basket having only one
apple."
[0072] When used herein to join a list of items, "or" denotes "at
least one of the items," but does not exclude a plurality of items
of the list. Thus, reference to "a picnic basket having cheese or
crackers" describes "a picnic basket having cheese without
crackers", "a picnic basket having crackers without cheese", and "a
picnic basket having both cheese and crackers." Finally, when used
herein to join a list of items, "and" denotes "all of the items of
the list." Thus, reference to "a picnic basket having cheese and
crackers" describes "a picnic basket having cheese, wherein the
picnic basket further has crackers," as well as describes "a picnic
basket having crackers, wherein the picnic basket further has
cheese."
[0073] Turning now to the drawings, FIGS. 1-6 each illustrate a
plurality of nodes that form wireless ad hoc networks in accordance
with common designation networking. The nodes in FIGS. 1-6 comprise
nodes N1, N2, N3, N4, N5 and a gateway node G1. In each
illustration, each node N1, N2, N3, N4 and N5 has a particular
shape (a circle or a triangle), indicating a particular common
designation that applies to that node, and the gateway node G1 has
a square shape. In FIGS. 1-6, some of the shapes are shown with
visual emphasis (i.e., with thicker lines, sometimes referred to
herein as being shown in bold), indicating generally that the nodes
represented by those shapes are active as set forth herein.
[0074] In accordance with the invention, a "node" generally refers
to a wireless radio frequency data communication device that
comprises a two-way communications component in the form of a
transceiver that receives and transmits information wirelessly with
one or more other nodes. The data communication device preferably
includes a low-power radio frequency ("LPRF") data communication
device that communicates via data packets. The transmission of the
data packets may utilize, for example, transmission control
protocol ("TCP"). The two-way communications component of the data
communication device also preferably is a standards-based radio
("SBR") and comprises, for example, a Wi-Fi, WiMAX, CDMA, WCDMA,
GSM, ZigBee, Ultra-Wideband, or Bluetooth radio. Indeed, in
connection with the one or more preferred embodiments described
below, the SBR preferably comprises a Bluetooth radio.
[0075] Generally, in receiving or transmitting information
wirelessly between two nodes, a communications link is established
between the SBRs of the two nodes and an electronic message then is
transmitted via the communications link. Following transmission of
the electronic message, the communications link is disconnected and
the SBRs return to an inactive state for power conservation.
Alternatively, the communications link established between the data
communication devices of the two nodes may be maintained, if
desired, in order to provide continuous communications between the
two nodes without having to reestablish a communications link
therebetween. Establishing a continuous communications link between
two nodes without having to reestablish the communications link
therebetween is particularly desirable, for instance, in
transmitting real time audiovisual content, or in providing real
time audiovisual communications between persons. Such
person-to-person communications further may be "two-way" when each
data communication device at each node includes dual radios. This
is particularly true when Bluetooth radios are utilized, which do
not include duplex capabilities. Thus, for example, maintaining
continuous communications between two nodes each employing dual
radios is particularly desirable if data packets for Voice-over-IP
("VoIP") services are to be wirelessly transmitted between the two
nodes. Once the continuous communications are no longer needed, the
communications link is disconnected and the SBRs return to an
inactive state for power conservation.
[0076] The data communication device of a node of the wireless
network may be mobile or fixed at a particular location, and the
data communication device may include an internal power supply
source or utilize an external power supply source. The data
communication device also may include an interface for
communicating with an associated sensor or other data acquisition
device, which sensor may or may not form part of the node. The data
communication device constituting the node also or alternatively
may be attached to an asset that is to be monitored and/or tracked;
alternatively, the data communication device constituting the node
may be permanently affixed to a structure for monitoring and/or
tracking assets that come within proximity thereto.
[0077] With respect to a "gateway" node, the gateway node
preferably is configured for direct electronic communication with a
network that is external to any ad hoc wireless network that may be
formed by the nodes themselves. Communications between the gateway
and the external network may be wireless or hard-wired and
comprise, for example, a network interface card that accepts a CAT
5 cable for Ethernet communications; a cellular transceiver for
communications via a cellular telephone network; a satellite
transceiver for communications via a satellite network; or any
combination thereof. The wired network itself may be a wide area
network ("WAN") and includes the Internet. Such a node is called a
"gateway" node because it serves as a gateway for other nodes in
communicating via the external network. A computer system further
may be disposed in electronic communication with the same wired
network, whereby the computer system and each node of the wireless
network may communicate with each other through the external
network, such as the WAN, and the one or more gateways. Moreover,
the computer system may include application software and a
database, and the computer system may record and maintains
information regarding the wireless network, nodes thereof, and/or
data received therefrom. Such a computer system is sometimes
referred to as a "server" and may be utilized to track and/or
monitor asset that may be associated with the nodes. If the nodes
are utilized simply for monitoring purposes irrespective of assets,
such a server may be utilized for responding to conditions that are
sensed by one or more of then nodes, including alerting appropriate
third parties to a sensed condition.
[0078] In alternative embodiments, the server may be combined with
a gateway node itself, which combination sometimes may be referred
to as a "gateway controller" or "GC". In such embodiments the
gateway controller performs the aforementioned functions of the
server. Also, the gateway controller preferably is still configured
to communicate with an external network WAN, thereby providing an
avenue for communicating from remote locations via the WAN with the
gateway controller in order to access information that is recorded
and maintained by the gateway controller.
[0079] In accordance with the invention, the nodes utilize common
designation networking in combination with wake-up technologies.
Common designation networking is perhaps best disclosed in the
incorporated U.S. Pat. Nos. 6,745,027 and 7,221,668. When the nodes
are associated with assets, common designation identifiers
representing attributes or characteristics of the assets are
typically used, which common designations often are referred to as
"class" designations. Similarly, ad hoc networks formed based
thereon are often referred to as "class-based" networks and
communications in such networks are often referred to as
"class-based" communications. In accordance with common designation
networking, a node screens each transmission for a data identifier
that represents a common designation of that node. The node does
not process, route, or respond to an incoming transmission if the
data identifier is not found. As will be appreciated, common
designation networking greatly reduces RF noise when many nodes are
within broadcast range of each other and greatly increase operating
life of mobile nodes that dependent on battery sources, as the
nodes do not needlessly respond to all transmissions, filtering out
and processing, routing, and/or responding to only those
transmission bearing its common designation.
[0080] As further disclosed in the incorporated references, it will
be appreciated that a node may have more than one common
designation at any given time, and that a common designation may
represent a subset or a superset of another common designation
(sometimes referred to as class and subclass).
[0081] The wake-up technologies that are utilized in accordance
with the invention are perhaps best disclosed in U.S. Pat. No.
7,209,771 and U.S. Patent Appl. Publication No. 2006/0287008. These
two incorporated references disclose alternative approaches for the
wake-up technologies that may be used.
[0082] Specifically, in incorporated U.S. Pat. No. 7,209,771, each
node of the wireless ad hoc network includes--in connection with
the SBR--a wake-up receiver that listens for a wake-up broadcast or
signal, referred to generally as a "wake-up broadcast," that
includes a common designation of that node. Upon receiving such a
wake-up broadcast, the wake-up receiver provides an electronic
signal that activates the SBR, which resides in a dormant state
(either off or in a reduced power standby mode) while the wake-up
receiver is listening for an applicable broadcast. The wake-up
receiver is a simplified receiver that draws much less current when
listening for an applicable broadcast compared to the current that
would be drawn by the SBR when listening for an applicable
broadcast. Hence, significant power conservation and long battery
life is achieved using such a wake-up receiver.
[0083] Furthermore, this wake-up receiver may screen only for a
predetermined common designation, as disclosed in U.S. Patent Appl.
Publication No. 2006/0287008. Alternatively, a more complicated
stepped wake up of the SBR may be performed using the wake-up
receiver, wherein the wake-up receiver first screens for one or
more criteria before screening for the common designation in the
wake-up broadcast. Such a stepped wake-up methodology is disclosed,
for example, in the incorporated U.S. Patent Appl. Publication No.
US 2006/0276161. Screening for criteria that is indicative of an
actual wake-up broadcast being received can be beneficial when
significant RF noise is present, whereby false indications of the
receipt of a wake-up broadcast can be reduced.
[0084] In incorporated U.S. Patent Appl. Publication No.
2006/0287008, a wake-up transceiver is disclosed. The wake-up
transceiver is similar to the aforementioned wake-up receiver, but
further includes a transmitter by which a wake-up broadcast may be
transmitted without necessarily having to activate the SBR. In the
data communication devices of U.S. Pat. No. 7,209,771, the SBR
sends a wake-up broadcast whereas, in U.S. Patent Appl. Publication
No. 2006/0287008, the wake-up broadcast may be sent by the wake-up
transceiver without having to activate the SBR. Avoiding booting up
of the SBR has been found to result in significant power savings,
and while the SBR has additional features and functionality not
provided by the wake-up transceiver, such features and
functionality are not required in transmitting a wake-up
broadcast.
[0085] As used herein, "Wake-Up Component" is intended to mean
either a wake-up receiver or wake-up transceiver, as disclosed in
these incorporated references, the data communication device of
each node of FIG. 1 preferably includes such a Wake-Up
Component.
[0086] Turning now to FIG. 1, node N5 is illustrated in bold, which
represents that the SBR of node N5 is active. More particularly,
node N5 is transmitting a wake-up broadcast ("WU") to nodes in the
broadcast range that have a "circle" common designation. The nodes
within the broadcast range of node N5 are illustrated within the
dashed circle of which node N5 is located at the center. Those
nodes include nodes N1, N2, and N3, all of which include a dormant
SBR as indicated by the lack of bold emphasis, and the wake-up
broadcast is received by the Wake-Up Component of each of these
nodes.
[0087] In accordance with an exemplary implementation, the wake-up
broadcast includes the data construct with the hexadecimal value
"00010051" as illustrated in FIG. 1. The pieces of information
contained within the data construct in this exemplary
implementation of the wake-up broadcast is illustrated in FIG. 7.
As shown therein, the first sixteen bits (i.e., the first four
digits of the hexadecimal value shown in FIG. 1) represent the
wake-up identifier portion of the wake-up broadcast. The next
twelve bits (i.e., the next three digits of the hexadecimal value
shown in FIG. 1) represent an identification of the node initiating
the wake-up broadcast. Finally, the last four bits (i.e., the final
digit of the hexadecimal value shown in FIG. 1) represent a rolling
transmission or message count sent by the originating node.
Accordingly, in interpreting the data construct with the
hexadecimal value "00010051" illustrated in FIG. 1, the first four
digits "0001" identify the common designation (in this case,
defined as corresponding to the "circle" common designation); the
next three digits "005" identify the node (in this case, defined as
corresponding to N5) that is initiating the wake-up broadcast; and
the last digit identifies a transmission or message count of "1".
For reference, various common designations, node IDs, and gateway
IDs in an exemplary implementation are shown in the tables of FIGS.
10 and 11, and are exemplary in nature only.
[0088] As will now be apparent, the wake-up broadcast includes
information in addition to that which is required merely to effect
the wake-up of desired nodes. In particular, the wake-up broadcast
includes networking information that may assist any node listening
to the wake-up broadcast in facilitating networking communications
itself.
[0089] Continuing with reference to FIG. 1, nodes N1 and N3 each
have the common designation of "circle," which is the common
designation identified in the wake-up broadcast transmitted by Node
N5. Thus, as shown in FIG. 2, the SBRs of these two nodes are
awakened by their respective Wake-Up Components and (1) each
propagates the wake-up broadcast received from node N5 by
transmitting a wake-broadcast with the same data construct value
00010051; and (2) each engages in Bluetooth communications with
Node N5 via the SBRs. The awakened state of the SBRs in nodes N1
and N3, as well as that of node N5, is represented by the bold
emphasis of nodes N1, N3, and N5 in FIG. 2.
[0090] It furthermore will be appreciated that, while node N2 was
within the range of the wake-up broadcasts of nodes N5 and N1,
respectively, no common designation of node N2 was included in the
data construct of either broadcast. Thus, node N2 did not "wake up"
in response to either broadcast. On the other hand, node N2 has
"heard" the wake-up broadcasts and has made note of the following
networking information revealed by such wake-up broadcasts: (1) the
presence of node N5 having the "circle" common designation within
one hop from node N2; and (2) the presence of another node having
the "circle" common designation within the broadcast range of node
N2.
[0091] FIG. 3 represents the next sequence of events following
those of FIG. 2. In this regard, FIG. 3 illustrates that node N4,
which has the common designation of "circle", responds to the
wake-up broadcast propagated by node N3. As shown in FIG. 3, the
SBR of node N4 is awakened by its Wake-Up Component and (1) node N4
propagates the wake-up broadcast received from node N3 by
transmitting a wake-broadcast with the data construct 00010051; and
(2) node N4 engages in Bluetooth communications with Node N3 via
the SBRs. The awakened state of the SBR of node N4 is represented
by the bold emphasis of node N4 in FIG. 3.
[0092] In addition, FIG. 3 illustrates that node N1 engages in
Bluetooth communications with the gateway G1. In this regard, the
gateway G1 preferably includes many, if not all, of the common
designations that are shared by a plurality of nodes, including the
"circle" and "triangle" common designations. This is illustrated in
the table of FIG. 11, wherein the gateway has an "active" status
for common designations identified by identifiers 1001-1006,
including identifier 1001, assigned to the "circle" common
designation, and 1005, assigned to the "triangle" common
designation. The gateway G1 preferably does not include active
status for common designations relating to the node attributes
shown in FIG. 1, nor for the common designations representing the
unique IDs of the nodes.
[0093] Accordingly, upon receiving the wake-up broadcast from node
N1 shown in FIG. 2, the SBR of the gateway G1 was awakened by the
Wake-Up Component of the node for engaging in Bluetooth
communications with node N1 as shown in FIG. 3, and its awakened
state is represented by the bold emphasis of the gateway G1 in FIG.
3. Furthermore, as shown, the wake-up broadcast is not propagated
by the gateway.
[0094] It should further be appreciated that a node does not
propagate the wake-up broadcast more than once. Each wake-up
broadcast is screened based on the common designation, node ID, and
transmission count from that node ID as identified in the data
construct of the broadcast, and a wake-up broadcast having a
matching data construct is not transmitted if there is an
indication that such a wake-up broadcast has already been
transmitted. Preferably, a list having a predetermined number of
entries is maintained, with the oldest entries being discarded as
new entries are added once the list has been populated.
[0095] FIG. 4 illustrates a period of inactivity of transmissions
between the nodes. During this period, all of the SBRs of the nodes
are dormant, as represented by the lack of any bold emphasis of any
of the nodes. During this period, external communications may be
occurring, for example with an external server based on the
Bluetooth communications between node N1 and gateway G1 illustrated
in FIG. 3.
[0096] FIG. 5 illustrates the next sequence of events in the
present example. In FIG. 5, the SBR of the gateway G1 has been
activated in response to a communication received from the external
network for receipt by node N5. The message may be, for example, an
acknowledgement, intended for node N5, of receipt of a message by a
server.
[0097] In response, the gateway G1 transmits a wake-up broadcast
that is targeted specifically for node N1. In this regard, the
gateway G1 preferably knows the pathway to node N5 based at least
upon the receipt of the message communicated via Bluetooth from
node N5 to the gateway G1 by way of node N1. Such pathway
identification preferably is accomplished using the deterministic
and nondeterministic methodologies disclosed, for example, in the
incorporated U.S. Patent Appl. Publication No. US 2007/0002792.
[0098] It furthermore will be appreciated that, although node N2
was within the range of the wake-up broadcast of gateway G1, no
common designation of node N2 is included in the data construct of
the broadcast (indeed, it was specifically targeted for node N1).
Thus, node N2 did not "wake up" in response to the broadcast and,
specifically, the SBR of node N2 was not activated. Nevertheless,
node N2 "heard" the wake-up broadcast from gateway G1 and made note
of the following networking information revealed by such wake-up
broadcast: (1) the confirmed presence of gateway G1 (identified by
node ID 0801) within a single hop from node N2; and (2) the
presence of node N1 (identified by the wake-up identifier "0101")
presumed by gateway G1 to be within the broadcast range of node
G1.
[0099] FIG. 6 illustrates node N1 transmission by node N1 of a
wake-up broadcast targeting node N5 and the consequent Bluetooth
communications engaged between node N1 and node N5. In particular,
the node N1 transmits a wake-up broadcast that is intended
specifically for node N5. Preferably, node N1 knows the pathway to
node N5 based at least upon the prior communications with node N1
illustrated in connection with FIGS. 1-2. Again, such pathway
identification preferably is accomplished using the deterministic
and nondeterministic methodologies disclosed, for example, in the
incorporated U.S. Patent Appl. Publication No. US 2007/0002792.
Also shown in FIG. 6, once the SBR of node N5 is awaken, Bluetooth
communications commence between the SBRs of node N5 and node
N1.
[0100] Additionally, it should again be noted that although node N2
is within the range of the wake-up broadcast transmitted by node
N1, no common designation of node N2 is included in the data
construct of the broadcast (indeed, it was specifically targeted
for node N5). Thus, node N2 did not "wake up" in response to the
broadcast and, specifically, the SBR of node N2 was not activated.
Nevertheless, node N2 "heard" the wake-up broadcast from node N1
and made note of the following networking information revealed by
such wake-up broadcast: (1) the confirmed presence of node N1
(identified by node ID 0101) within a single hop from node N2; and
(2) the presence of node N5 (identified by the wake-up identifier
"0105") presumed by node N1 to be within the broadcast range of
node N1.
[0101] As referenced previously, FIG. 7 illustrates an exemplary
data construct as found in the wake-up broadcasts (WU) of FIGS.
1-6. As described above, the eight-digit number shown in brackets
by "WU" represents the hexadecimal equivalent of the 32-bit data
construct format shown in FIG. 7. Moreover, while the data
construct shown is 32 bits, it will be appreciated that any number
of bits may be selected depending upon the number of possible
wake-up identifiers, node IDs, and counts that are desired to be
accommodated in implementing the present invention, and depending
upon any other networking information that may be desired to be
included in the wake-up broadcast.
[0102] For example, FIG. 8 illustrates another exemplary data
construct that may be included in the wake-up broadcast (WU) in
accordance with the present invention. In this example, the first
32 bits of the data construct represent the same pieces of
information represented by the first 32 bits of the data construct
of FIG. 7; however, the data construct includes an additional eight
bits (for a total of 40 bits) wherein the additional last eight
bits represent an encryption key. The encryption key may be
utilized in symmetric or asymmetric encryption. In some
contemplated embodiments, the encryption key is a public key.
Preferably, each authorized data communication device is configured
to use the encryption key to decrypt one or more pieces of the
information contained in the data construct. The encrypted portions
may include, for example, the wake-up identifier and/or the node
ID. Nodes or other devices that do not have the ability to decrypt
the information will not be able to contact the nodes or join the
network. Moreover, hacking the network will be more difficult.
[0103] Instead of, or in addition to, using the encryption key to
decrypt one or more portions of the wake-up broadcast, the
encryption key may be utilized by the SBR to decrypt communications
conducted via the SBR of the node. Provision of the encryption key
via wake-up broadcasts for use in decrypting communications via
SBRs represents an additional layer of network security, as SBRs
may not necessarily be able to communicate with Wake-Up Components,
especially when Wake-Up Transceivers are utilized. In such
scenarios, two different avenues of communications are enabled with
the encryption key being provided through one avenue for use in
decrypting communications received via the second avenue.
[0104] It also should be appreciated that the encryption key could
be used to encrypt communications by the node in addition to or
rather than decrypting communications.
[0105] Still yet, FIG. 9 illustrates a third exemplary data
construct that may be included in the wake-up broadcast (WU) in
accordance with the present invention. In this example, the first
32 bits of the data construct represent the same pieces of
information represented by the first 32 bits of the data construct
of FIG. 7; however, the data construct includes an additional eight
bits (for a total of 40 bits) wherein the additional last eight
bits represents a payload of the wake-up broadcast in which a
message or other data may be transmitted via the Wake-Up Components
of the nodes. The payload data may include network information or
may include information unrelated to the network itself. Such
payload information may include, for example, application-specific
data for an application executed by a destination node, an
indication of the status of a sensor associated with a node (such
as a seal or temperature sensor), and the like.
[0106] FIG. 10 illustrates an exemplary table of wake-up
identifiers that may be maintained, for example, by node N2 in
accordance with the present invention. As shown in FIG. 10, node N2
includes the following common designations: "0102" representing the
unique node ID 102 of the node N2; "1000" representing a general
wake-up identifier which all nodes preferably share; "1002"
representing a "polygon" common designation; "1005" representing a
"triangle" common designation; "1006" representing an "isosceles
triangle" common designation; "3001" representing an attribute of
the node, namely, that a gateway is available for communications
to/from the node; and "3002" representing another attribute of the
node, namely, that the node is located for communications directly
with a gateway.
[0107] It will be appreciated that information noted by a node may
be utilized to effect various functions. For example, as was
described previously, node N2 "heard" the wake-up broadcast from
gateway G1 and made note of certain networking information,
including the confirmed presence of gateway G1 (identified by node
ID 0801) within a single hop from node N2. If such information was
previously unknown to node N2 (i.e., if the status for the wake-up
identifier "3002" was previously set to inactive), then node N2
may, in response to the discovery of this information, change the
status from inactive to active.
[0108] It will be understood that the foregoing wake-up identifiers
are presented simply for illustration of the invention only. One of
countless alternative implementations is described in incorporated
U.S. provisional patent application Ser. No. 60/890,990. Indeed, it
is certainly contemplated that commercial implementations of the
invention will include different identifiers more commercially
meaningful and relevant than mere geometric shapes. For example,
commercial implementations of the present invention are
particularly suited for use in asset tracking networks, asset
monitoring networks, sensor data-acquisition networks, and
combinations thereof. Such networks are disclosed, for example, in
incorporated U.S. Pat. Nos. 6,934,540 and 6,745,027, both of which
relate to class-based networks for tracking and/or monitoring
assets.
[0109] For example, in asset tracking/monitoring applications, such
different wake-up identifiers could include classes corresponding
to televisions, appliances, and consumer electronics; with
supersets including Sony, Whirlpool, and Phillips; and with subsets
including plasma televisions, dishwashers, and electric razors. In
sensor network implementations, such different wake-up identifiers
could include common designations corresponding to each different
type of sensor; each different location or area of the sensors; and
each manufacturer of the sensors. If the sensor networks are
deployed for or on the behalf of third parties as part of
commercial services offered, then wake-up identifiers further could
include common designations corresponding to each different
customer or each different location of the customer where such
services are utilized.
[0110] FIG. 11 illustrates an exemplary table of wake-up
identifiers that may be maintained by gateway G1 in accordance with
the present invention. As shown in FIG. 11, gateway G1 includes the
following common designations: "0801" representing the unique
gateway ID 101 of the gateway G1; "1000" representing a general
wake-up identifier which all nodes (including gateway nodes)
preferably share; "1001" representing a "circle" common
designation; "1002" representing a "polygon" common designation;
"1003" representing a "rectangle" common designation; "1004"
representing a "square" common designation; "1005" representing a
"triangle" common designation; and "1006" representing an
"isosceles triangle" common designation.
[0111] As will now be appreciated from the foregoing description,
nodes in common designation networks that utilize Wake-Up
Components have great listening capacity. By simply listening with
its Wake-Up Component and recording networking information gleaned
from wake-up broadcasts, a node can greatly improve its performance
as well as the overall network performance. Indeed, many advantages
can be gained by simply facilitating network communications. By
providing network information in the wake-up broadcasts, nodes are
able to more efficiently make network connections and communicate
with desired nodes and/or an external network. For example, just by
listening and noting network information in a wake-up broadcast, a
node can determine that it is only a single hop to a gateway
without having to do initiate its own pathway query. The time
previously required in certain situations for a node or gateway to
communicate with a data communications device that is within range
thus can be reduced. The opportunities for RF collision, which
could delay network communications, also is reduced. Battery power
also is conserved by reducing the number of times that an SBR needs
to be activated from its dormant state. In contrast to these
benefits, the small amount of networking data provided in the
wake-up broadcasts does not overburden the simple Wake-Up
Components, and thus the invention provides important advantages
with little cost.
[0112] Turning now to the drawings, FIG. 12 is representative of
locations, states, and state transitions of radio frequency
communication devices shown at a first time in accordance with one
or more preferred embodiments of the present invention.
[0113] In this regard, nine radio frequency communication devices
10 labeled "RSI R.sub.1" through "RSI R.sub.9" are shown in FIG.
12. Each radio frequency communication device 10 preferably
comprises a movable remote sensor interface or "RSI" that includes
its own internal power source, such as a battery. Each RSI
preferably is active or at least semi-active, and each RSI
preferably is disposed in electronic communication with one or more
sensors through one or more interfaces of the RSI for receiving
sensor signals including, for example, sensor-acquired data. Such
sensors may comprise, for example, temperature sensors, motion
sensors, accelerometer sensors, and GPS receivers.
[0114] The nine communication devices 10 are distributed among m
different physical areas (m being some integer greater than 1).
These areas are represented by areas 12, 14, 16, 18 illustrated in
FIG. 12. Each area may be at the same location as another area or
at a different location as another area. For instance, area 12 may
represent a boat dock (area) at a port of entry (location) and area
14 may represent a truck loading dock (area) at the same port of
entry (location). Alternatively, area 12 may represent a warehouse
(area) in Charleston, S.C. (location) and area 14 may represent a
warehouse (area) in San Diego, Calif. (location). Moreover, area 16
may represent the cargo area (area) of a transport vehicle
(location) in route between area 12 in Charleston and area 14 in
San Diego, and the location thus need not be stationary. In this
example, the location is dynamic and changes as the transport
vehicle moves between Charleston and San Diego.
[0115] Furthermore, in accordance with one or more aspects of the
present invention, at least one of the sensors associated with an
RSI is utilized to indicate the likely removal of the RSI from an
area, as discussed in greater detail below.
[0116] Each of them areas includes at least one gateway and,
accordingly, there are at least m gateways represented in FIG. 12.
These gateways are represented by gateways 20, 22, 24, 26. In this
regard, gateway 20 is illustrated as being within area 12 and is
labeled "Gateway G.sub.1"; gateway 22 is illustrated as being
within area 14 and is labeled "Gateway G.sub.2"; gateway 24 is
illustrated as being within area 16 and is labeled "Gateway
G.sub.3"; and gateway 26 is illustrated as being within area 18 and
is labeled "Gateway G.sub.m".
[0117] Each gateway 20, 22, 24, 26 preferably is disposed in
electronic communication with one or more servers labeled,
respectively, "Server S.sub.1", "Server S.sub.2", and "Server
S.sub.n", wherein n is some integer greater than 1. The servers are
represented by server 28, 30, 32 and may be remotely located to
each other. The servers 28, 30, 32 also may be remotely located to
the gateways 20, 22, 24, 26. The electronic communication between
the servers and the gateways may be accomplished, for example, by
way of cellular communications, satellite communications, and/or
Internet communications.
[0118] Preferably, the communication devices 10 are associated with
assets, and the servers 28, 30, 32 collectively include the
programs and databases of one or more asset tracking systems for
tracking and/or monitoring of the assets with which the
communication devices 10 are associated. The gateways and the
communication devices further preferably form common designation
networks and, more preferably, class based networks.
[0119] With further reference to FIG. 12, each gateway 20, 22, 24,
26 is shown at a first time t.sub.1 in FIG. 12 as making a
respective radio frequency transmission that preferably awakens
each communication device 10 from a sleep or standby mode, as
appropriate. In this regard, this radio frequency transmission
preferably comprises a wakeup broadcast that includes a common
designation comprising a class designation. If the class
designation matches a class designation maintained in a table of
class designations of a respective communication device 10, then
that communication device 10 awakens and makes a radio frequency
transmission in response. For brevity, a radio frequency
transmission that is a wakeup broadcast and that includes a class
designation is sometimes referred to herein as a "Class-Present
Wakeup Broadcast" and is simply labeled "Present" in the drawings.
As will be appreciated, the Class-Present Wakeup Broadcasts
represent a particular type of--and if a subset of--Present
Broadcasts.
[0120] Additionally, the transmission in response to the
Class-Present Wakeup Broadcast by the respective communication
device 10 preferably includes an identification of the respective
communication device 10. Such an identification may uniquely
identify the respective communication device 10 or radio of the
communication device 10. Alternatively, the identification may
uniquely identify one or more assets with which the communication
device 10 is associated in an asset tracking system, especially
when the communication device is a wireless reader tag (WRT) or
similar device. Alternatively, the identification may serve to
distinguish the respective communication device 10 from one or more
other communication devices 10 without uniquely identifying the
respective communication device 10 from all other communication
devices 10.
[0121] The Class-Present Wakeup Broadcast made by each gateway 20,
22, 24, 26 is received by each communication device within the
respective area of the gateway, and each communication device 10 is
shown as responding to the Class-Present Wakeup Broadcast, wherein
each response is represented by a lightning bolt.
[0122] As will be appreciated, an RSI further can retransmit the
Class-Present Wakeup Broadcast to other RSIs that fall outside of
the gateway range, thereby expanding the effective range of
communications with the gateway. Communications between a gateway
and one or more RSIs outside of the gateway's range, via one or
more RSIs within range, is disclosed in one or more of the
incorporated references but, for clarity, is not shown in the
present drawings. Communications between an RSI and a gateway
further may be through other RSIs even when all RSIs are within
range of the gateway, as disclosed, for example, in many of the
incorporated references such as U.S. Pat. Nos. 6,745,027 and
6,934,540.
[0123] As will be appreciated from the following detailed
description, and in accordance with preferred embodiments of the
invention, the fact that each of the nine communication devices 10
responds to the Class-Present Wakeup Broadcast indicates that none
of the nine communication devices 10 likely were present in the
areas 12,14,16,18 as shown in FIG. 12 at the time of a
Class-Present Wakeup Broadcast first preceding that at time
t.sub.1. Furthermore, each communication device 10 responds to a
Class-Present Wakeup Broadcast, as appropriate, regardless of the
number of times that the communication device 10 has previously
responded. Whether a communication device 10 responds preferably is
not a function of the number of times that communication device 10
has responded in the past.
[0124] The Class-Present Wakeup Broadcast may be performed by each
respective gateway "on demand" upon receipt of an instruction to
such effect from one of the servers 28, 30, 32. Alternatively, each
gateway may be configured to make the Class-Present Wakeup
Broadcast in accordance with a predetermined schedule, such as at
regular intervals of time. If timers are utilized, then the timers
of the gateways determine the resolution within which a
communication device is identified as having arrived at a
particular area. Still yet, a particular gateway may be triggered
to make a Class-Present Wakeup Broadcast by one or more sensors,
such as motion, optical, or infrared sensors. Indeed, while
gateways are concurrently shown in the drawings as making
Class-Present Wakeup Broadcasts, a gateway nevertheless may make a
Class-Present Wakeup Broadcast independent of one or more other
gateways.
[0125] The transmissions made in response to the Class-Present
Wakeup Broadcast and, in particular, the identification included in
each response, is communicated through each gateway to an
appropriate one or more of the servers 28, 30, 32 that is tasked
with keeping track of the location of each communication device 10.
Based upon the particular gateway from which a respective
identification is received, the server may then determine that the
respective communication device 10 corresponding to that
identification is within the area of that particular gateway.
[0126] Accordingly, from the responses to the Class-Present Wakeup
Broadcasts shown in FIG. 12, the appropriate server determines
that: RSIs R.sub.1, R.sub.2, and R.sub.3 are within the area of
Gateway G.sub.1; RSIs R.sub.4 and R.sub.5 are within the area of
Gateway G.sub.2; RSIs R.sub.6, R.sub.7, and R.sub.8 are within the
area of Gateway G.sub.3; and RSI R.sub.9 is within the area of
Gateway G.sub.m. Preferably, the server records and maintains such
location information for each of the communication devices 10.
[0127] Thereafter, each gateway 20, 22, 24, 26 is shown at a second
time subsequent to the first time in FIG. 13 as making a respective
subsequent Class-Present Wakeup Broadcast. Again, the Class-Present
Wakeup Broadcast made by each gateway 20, 22, 24, 26 is received by
each communication device within the respective area of the
gateway; however, none of the communication devices 10 is shown as
responding to the Class-Present Wakeup Broadcast. In accordance
with preferred embodiments of the invention, none of the
communication devices 10 respond to the Class-Present Wakeup
Broadcast because each has already responded to a Class-Present
Wakeup Broadcast at time t.sub.1, and each has yet to move from the
respective area in which it was located since that time.
[0128] As will be appreciated, the server tasked with keeping track
of the location of each communication device 10 receives no
identification from any communication device 10 via the gateways
20, 22, 24, 26 and, based thereon, does not update any location
information for any of the communication devices 10. Having
received no identifications in response to the Class-Present Wakeup
Broadcasts, the server assumes that none of the communication
devices 10 have been moved from their respective areas as recorded
by the server.
[0129] At a third time subsequent to the second time, as shown in
FIG. 14, communication device 10 labeled as RSI R.sub.2 is moved
from the area 12 of the gateway 20 (Gateway G.sub.1). The RSI
R.sub.2 preferably is disposed in electrical communication with a
motion sensor through an interface thereof and, upon being moved,
the RSI R.sub.2 preferably receives sensor-acquired information
from the motion sensor that indicates the movement of the RSI
R.sub.2. Such electrical communication may be wired or wireless,
and the sensor may be internal or external to a housing of the
communication device. The RSI R.sub.2 preferably is configured,
upon receipt of such sensor-acquired information through the
interface, to make a radio frequency transmission including an
identification thereof to an appropriate server via the gateway 20.
The server preferably is the server that records and maintains the
location information for each of the communication devices 10 and,
upon receipt of the communication from RSI R.sub.2, the server
preferably records information pertaining to such communication. In
particular, the server preferably records information indicating
movement of RSI R.sub.2 and the time t.sub.3 of such movement. The
movement is presumed to indicate the likely removal of the RSI
R.sub.2 from the area. Other sensors, or a combination of sensors,
further can be used to indicate such likely removal. For example,
the combined readings from both a motion sensor and a temperature
sensor could be used to indicate likely removal of the
communication device from a particular area. Alternatively,
temperature rather than motion could be used as an indicator that
the communication device likely has moved from a controlled
environment of a particular area.
[0130] At a fourth time subsequent to the third time, as shown in
FIG. 15, communication device 10 labeled as RSI R.sub.4 moved from
the area 14 of the gateway 22 (Gateway G.sub.2). The RSI R.sub.4
preferably is disposed in electrical communication with a motion
sensor through an interface thereof and, upon being moved, the RSI
R.sub.4 preferably receives sensor-acquired information from the
motion sensor that indicates the movement of the RSI R.sub.4. Such
electrical communication may be wired or wireless, and the sensor
may be internal or external to the RSI. The RSI R.sub.4 preferably
is configured, upon receipt of such sensor-acquired information
through the interface, to make a radio frequency transmission
including an identification thereof to an appropriate server via
the gateway 22. The server preferably is the server that records
and maintains the location information for each of the
communication devices 10 and, upon receipt of the communication
from RSI R.sub.4, the server preferably records information
pertaining to such communication. In particular, the server
preferably records information indicating movement of RSI R.sub.2
and the time t.sub.4 of such movement.
[0131] At a fifth time subsequent to the fourth time, as shown in
FIG. 16, the gateways 20, 22, 24, 26 again make Class-Present
Wakeup Broadcasts. As will be appreciated, none of the
communication devices 10 respond to the Class-Present Wakeup
Broadcast that have not moved since the first time t.sub.1; such
communications generally would be unnecessary and would thus
needlessly drain power sources of the communication devices 10. On
the other hand, RSI R.sub.2 which was moved at time t.sub.3 has
since moved into the area of gateway 24 (Gateway G.sub.3) by time
t.sub.5 and, in response to the Class-Present Wakeup Broadcast
received from gateway 24, the RSI R.sub.2 does make a responsive
transmission that includes an identification thereof. As a result
of this responsive transmission, the server tracking the location
information of RSI R.sub.2 updates the location information to
indicate that RSI R.sub.2 now is in area 16 as of time t.sub.5. RSI
R.sub.4, on the other hand, did not respond to the Class-Present
Wakeup Broadcasts and, as such, its absence from areas 12, 14, 16,
18 is identified. It further deemed that it was moved from area 14
at time t.sub.4.
[0132] At a sixth time subsequent to the fifth time, as shown in
FIG. 17, communication device 10 labeled as RSI R.sub.9 is moved
from the area 18 of the gateway 26 (Gateway G.sub.m). The RSI
R.sub.9 preferably is disposed in electrical communication with a
motion sensor through an interface thereof and, upon being moved,
the RSI R.sub.9 preferably receives sensor-acquired information
from the motion sensor that indicates the movement of the RSI
R.sub.9. Such electrical communication may be wired or wireless,
and the sensor may be internal or external to the RSI. The RSI
R.sub.9 preferably is configured, upon receipt of such
sensor-acquired information through the interface, to make a radio
frequency transmission including an identification thereof to an
appropriate server via the gateway 26. The server preferably is the
server that records and maintains the location information for each
of the communication devices 10 and, upon receipt of the
communication from RSI R.sub.9, the server preferably records
information pertaining to such communication. In particular, the
server preferably records information indicating movement of RSI
R.sub.9 and the time t.sub.6, of such movement.
[0133] At a seventh time subsequent to the sixth time, as shown in
FIG. 18, the gateways 20, 22, 24, 26 again make Class-Present
Wakeup Broadcasts. As will be appreciated, none of the
communication devices 10 respond to the Class-Present Wakeup
Broadcast that have not moved since the preceding Class-Present
Wakeup Broadcast at time t.sub.5; such communications generally
would be unnecessary and would thus needlessly drain power sources
of the communication devices 10. On the other hand, RSI R.sub.9
which was moved at time t.sub.6 has since moved into the area 14 of
gateway 22 (Gateway G.sub.2) by time t.sub.7 and, in response to
the Class-Present Wakeup Broadcast received from gateway 22, the
RSI R.sub.9 does make a responsive transmission that includes an
identification thereof. As a result of this responsive
transmission, the server tracking the location information of RSI
R.sub.9 updates the location information to indicate that RSI
R.sub.9 now is in area 14 as of time t.sub.7.
[0134] Additionally, RSI R.sub.4 which was moved at time t.sub.4
has moved into the area 1 of gateway 20 (Gateway G.sub.1) by time
t.sub.7 and, in response to the Class-Present Wakeup Broadcast
received from gateway 20, the RSI R.sub.4 does make a responsive
transmission that includes an identification thereof. As a result
of this responsive transmission, the server tracking the location
information of RSI R.sub.4 updates the location information to
indicate that RSI R.sub.4 now is in area 10 as of time t.sub.7.
[0135] Thereafter, each gateway 20, 22, 24, 26 is shown in FIG. 19
making a respective subsequent Class-Present Wakeup Broadcast at an
eighth time subsequent to the seventh. Again, the Class-Present
Wakeup Broadcast made by each gateway 20, 22, 24, 26 is received by
each communication device within the respective area of the
gateway; however, none of the communication devices 10 is shown as
responding to the Class-Present Wakeup Broadcast. In accordance
with preferred embodiments of the invention, none of the
communication devices 10 responds to the Class-Present Wakeup
Broadcast because each communication device 10 has already
responded as late as time t.sub.7 to a previous Class-Present
Wakeup Broadcast and has yet to be moved since such time of
response. Accordingly, no responsive transmissions are needlessly
made by any of the communication devices 10.
[0136] Each of the communication devices 10 shown in FIGS. 12-19
preferably operates in at least two states. In a first state, a
communication device 10 responds to receipt of a Class-Present
Wakeup Broadcast from a gateway 20, 22, 24, 26 by making a
transmission that includes an identification thereof. After this
responsive transmission, the communication device 10 preferably
enters a second state in which it does not respond to Class-Present
Wakeup Broadcasts. The communication device 10 preferably remains
in this second state until sensor-acquired information received
through an interface thereof indicates that a predefined condition
has occurred, such as movement of the communication device 10. Upon
the occurrence of the predefined condition, the communication
device 10 preferably makes a transmission that includes an
indication of the occurrence of the predefined condition as well as
an identification of the communication device 10. Upon making the
transmission, the communication device 10 preferably enters the
first state.
[0137] During each of the two states, the communication device 10
still wakes up and/or responds to any transmission that includes a
common designation (such as a class designation) that matches a
common designation of the communication device 10. Preferably, each
communication device 10 keeps a table of applicable common
designations to which it belongs. In this respect, a common
designation preferably is used to represent the Class-Present
Wakeup Broadcast and this common designation is either enabled or
disabled in the table as maintained by the communication device 10
depending upon whether the communication device 10 should respond
to a Class-Present Wakeup Broadcast that is next received.
[0138] Specifically, after the communication device 10 has made a
responsive transmission to a Class-Present Wakeup Broadcast, the
communication device 10 preferably enables a motion sensor,
disables the "present" common designation in its table, and waits
to be awoken upon an indication of movement from the motion sensor.
Furthermore, the enablement of the motion sensor and the
disablement of the "present" common designation in its table may be
automatically performed by the communication device itself
following its response to the Class-Based Wakeup Broadcast, or may
be performed by the communication device in direct response to
instructions received from a server following the identification of
the presence of the RSI to the server.
[0139] Thereafter, once the communication device 10 moves, the
communication device 10 is awoken by the motion sensor and
communicates, via a respective gateway, an indication of such
movement to the appropriate server. The communication device 10
also then disable the motion sensor and enables the "present"
common designation for waking up of the communication device 10 for
response to the next Class-Present Wakeup Broadcast.
[0140] This algorithm for entering the two different states enables
the communication device 10: to "check in" when it arrives within
an area of a gateway; to remain off or in standby after it has
"checked in" in order to conserve internal power and avoid spurious
transmissions; and to alert an appropriate server if the
communication device 10 is moved.
[0141] A benefit of at least one embodiment of the invention is the
avoidance of unnecessary and/or undesired radio frequency
transmissions during air shipments in a cargo area of an airplane.
Specifically, when communication devices 10, preferably associated
with assets being tracked and/or monitored, are loaded into the
cargo area of an airplane, a Class-Present Wakeup Broadcast is made
in order to identify the communication devices present for taking
inventory of the cargo. An instruction then is broadcast causing
the communication devices to enter the second state, in which the
motion sensors then are disabled. A Class-Present Wakeup Broadcast
is not made until after the airplane has arrived at its intended
location.
[0142] Since the motion sensor is turned off when the "present"
common designation is enabled, the communication device 10 will not
continuously try to report back to the server while it is in motion
in the airplane. During movement, such as that associated with air
transportation, the communication device 10 thus remains in a power
conservation mode until it comes within range of the next gateway
and receives a Class-Present Wakeup Broadcast.
[0143] As will be appreciated from the foregoing description, the
movement of a communication device 10 is tightly monitored by one
or more servers, since any communication device 10 within range of
a gateway 20, 22, 24, 26 reports when a predefined condition, e.g.,
movement, has occurred that indicates that it has been likely moved
out of the respective area in which it was residing. Moreover,
unnecessary transmissions in response to Class-Present Wakeup
Broadcasts are avoided when a communication device 10 has not moved
out of the respective area in which it resides.
[0144] In alternatives to the arrangements represented in FIGS.
12-19, the n servers can be consolidated into a single server;
and/or one or more servers can be combined with one or more
gateways. Such changes may reduce networking costs, delays, and
overhead associated with asset tracking systems, but the
flexibility, capabilities, and/or robustness of the systems
likewise may be reduced.
[0145] One or more aspects of the invention further may be utilized
with a single area for maintaining visibility of assets within the
single area without regard to visibility of the assets in other
areas, if desired.
[0146] Another benefit of at least one embodiment of the invention
is the ability to synchronize reporting from a plurality of radio
frequency communication devices to a server. In this respect, radio
frequency communication devices preferably communicate data that
otherwise is being stored to a server concurrently when responding
to a Present Broadcast. The concurrent communication of the data
with a Present Response obviates the need for the communications
device to wake-up at a later time for the specific purposes of
communicating the stored data. As such, a group of communication
devices can be manipulated, for example, into the first state such
that each responds to a Present Broadcast by communicating not only
a Present Response, but the stored data at each respective
communication device. Such manipulation into the first state can
occur, for example, by creating a predetermined condition (e.g.,
change in temperature, change in location, or movement), resulting
in sensor signals causing the communication devices to enter the
first state from the second state; and/or by broadcasting an
instruction to the communication devices to enter the first
state.
[0147] In view of the foregoing, one or more benefits of one or
more aspects of the present invention include: an increased battery
life; the ability to transport assets by land, sea, or air without
unnecessary or unwanted transmissions from the radios associated
with the assets; the ability to still communicate "on demand" with
a particular asset based on a common designation or class; the
ability to determine assets newly arrived within an area "on
demand" independent of any broadcasts at regular time intervals;
the ability of an asset to "hide" from unauthorized persons by not
needlessly identifying its presence in response to a general radio
frequency broadcast; and the ability to determine when an asset is
moved from an area once the asset has been identified as having
arrived within the area.
[0148] Based on the foregoing description, it will be readily
understood by those persons skilled in the art that the present
invention is susceptible of broad utility and application. Many
embodiments and adaptations of the present invention other than
those specifically described herein, as well as many variations,
modifications, and equivalent arrangements, will be apparent from
or reasonably suggested by the present invention and the foregoing
descriptions thereof, without departing from the substance or scope
of the present invention. Accordingly, while the present invention
has been described herein in detail in relation to one or more
preferred embodiments, it is to be understood that this disclosure
is only illustrative and exemplary of the present invention and is
made merely for the purpose of providing a full and enabling
disclosure of the invention. The foregoing disclosure is not
intended to be construed to limit the present invention or
otherwise exclude any such other embodiments, adaptations,
variations, modifications or equivalent arrangements, the present
invention being limited only by the claims appended hereto and the
equivalents thereof.
* * * * *