Note: Descriptions are shown in the official language in which they were submitted.
CA 02831119 2013-10-23
IMPROVED USE OF A MOBILE DATA COLLECTION DEVICE
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent
Application No.
61/727,552, filed November 16, 2012; and U.S. Patent Application Serial No.
13/716,356 filed
December 17, 2012; which are both incorporated herein by reference in its
entirety.
TECHNICAL BACKGROUND
[0002] The reading of electrical energy, water flow, and gas usage has
historically been
accomplished with human meter readers who came on-site and manually documented
meter
readings. Over time, this manual meter reading methodology has been enhanced
with walk by or
drive by reading systems that use radio communications to and from a mobile
collector device in
a vehicle. Recently, there has been a concerted effort to accomplish meter
reading using fixed
communication networks that allow data to flow from the meter to a host
computer system
without human intervention.
[0003] Automated systems, such as Automatic Meter Reading (AMR) and Advanced
Metering
Infrastructure (AMI) systems, may use radio frequency (RF) signals to collect
data from
transponders attached to meters that measure usage of resources, such as gas,
water and
electricity. AMR systems use a mobile interrogator, such as a handheld
computer equipped with
RF technology or a vehicle-based RF system, to collect meter data. Such
systems may employ a
number of different infrastructures for collecting this meter data from the
meters. For example,
some automated systems obtain data from the meters using a fixed wireless
network that
includes, for example, a central node, e.g., a collection device, in
communication with a number
of endpoint nodes (e.g., meter reading devices (MRDs) connected to meters). At
the endpoint
nodes, the wireless communications circuitry may be incorporated into the
meters themselves,
such that each endpoint node in the wireless network comprises a meter
connected to an MRD
that has wireless communication circuitry that enables the MRD to transmit the
meter data of the
meter to which it is connected. The wireless communication circuitry may
include a transponder
that is uniquely identified by a transponder serial number. The endpoint nodes
may either
transmit their meter data directly to the central node, or indirectly though
one or more
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intermediate bi-directional nodes that serve as repeaters for the meter data
of the transmitting
node.
[0004] Some networks may employ a mesh networking architecture. In such
networks, known
as "mesh networks," endpoint nodes are connected to one another through
wireless
communication links such that each endpoint node has a wireless communication
path to the
central node. One characteristic of mesh networks is that the component nodes
can all connect to
one another via one or more "hops." Due to this characteristic, mesh networks
can continue to
operate even if a node or a connection breaks down. Accordingly, mesh networks
are self-
configuring and self-healing, significantly reducing installation and
maintenance efforts.
[0005] Data collection systems such as electric, gas, and water utility
systems tend to fall into
two classifications: fixed or mobile network. Each has advantages and
disadvantages. A fixed
network typically has a tree structure with endpoints at the extreme ends of
the tree. These
endpoints relay their data toward a central head end by passing data first
through a local area
network (LAN) including other endpoints, repeaters, and collectors, and then
through a wide area
network (WAN) to the head end. Some units, such as electric meters, in a fixed
network are
always on. Other units, such as sleepy gas meters, water meters, and in-home
modules, are
battery operated and periodically receive a wake-up signal to tie into the
network. This periodic
wake-up process can be unilateral at the discretion of the endpoint or the
result of a wake-up
process initiated by adjacent always-on devices.
[0006] A mobile network can be drive-by, fly-by, or walk-by in nature and
typically involves a
mobile interrogator traveling a predetermined route to gather data from
endpoint devices in
residential and commercial locations. The mobile interrogator may also issue
commands to the
endpoint devices. The endpoint devices may include water, gas, and electric
metering and control
devices, such as thermostats and load control devices. There is typically
little or no
communication between endpoint devices themselves, and each endpoint device
typically
maintains its own history of data for the past collection period. The mobile
interrogator wakes up
the endpoint devices for the communication exchange. Alternatively, the
devices may
unilaterally transmit their data periodically so that the mobile interrogator
can receive the data
whenever it travels by. The collected data is passed from the mobile
interrogator to a route
manager, and then up to a head end that interfaces to a utility billing
system.
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SUMMARY OF THE DISCLOSURE
[0007] According to various embodiments, the capabilities of a mobile
interrogator can be
enhanced. As a result, the performance of both fixed and mobile networks can
be improved. In
addition, a hybrid system can be realized that provides a utility company with
advantages of both
fixed and mobile networks.
100081 One embodiment is directed to a system for hybrid employment of fixed
network and
mobile network communications. The system includes a plurality of
communication nodes. At
least some of the communication nodes operate in a fixed network mode using
one or more fixed
wireless network communication protocols. At least some other of the
communication nodes
operate in a mobile mode in which they transmit meter data to a mobile device
using one or more
mobile communication protocols. The mobile device is configured to communicate
with the
mobile mode communication nodes using the one or more mobile communication
protocols. The
mobile device is further configured to communicate with the fixed network mode
communication nodes using the one or more fixed wireless network communication
protocols.
[0009] Another embodiment is directed to a mobile device comprising a display
and a user
interface presented at least partially using the display. The user interface
may include a
representation of a plurality of communication nodes, at least some of the
communication nodes
operating in a fixed network mode using one or more fixed wireless network
communication
protocols, and at least some other of the communication nodes operating in a
mobile mode in
which they transmit meter data to the mobile device using one or more mobile
communication
protocols. The user interface may employ different audio and/or visual
indicators to provide
information used by the mobile device to communicate with both the fixed
network mode
communication nodes and the mobile mode communication nodes.
[0010] Yet another embodiment is directed to a method for improved route
navigation for
traversing meters in a metering network. One or more meter route preference
criteria and one or
more meter attribute filters are received. The meter route preference criteria
describe one or
more user preferences for navigating a selected group of meters. The meter
attribute filters
enable the selected group of meters to be filtered out from a plurality of
meters. A route for
traversing the selected group of meters is generated in accordance with the
meter route
preference criteria and the meter attribute filters.
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[0011] Various embodiments may realize certain advantages. For example, in a
fixed network,
a mobile interrogator device can be used as a substitute for a collector or
repeater to collect data
from endpoint devices. In a mobile network, a mobile interrogator device can
improve travel
speeds by taking advantage of fixed network type devices that are deployed in
a mobile network.
In both fixed and mobile networks, a mobile interrogator device can provide a
variety of
communication paths, including both LAN and WAN communications. In this way,
utility
companies can blur the boundaries of fixed and mobile networks and selectively
operate their
networks in a fixed mode, a mobile mode, or both modes simultaneously.
Advantageous
performance and improved reliability relative to some conventional networks
can be realized as a
result.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The foregoing summary, as well as the following detailed description of
various
embodiments, is better understood when read in conjunction with the appended
drawings. For
the purpose of illustrating the invention, there are shown in the drawings
exemplary
embodiments of various aspects of the invention; however, the invention is not
limited to the
specific methods and instrumentalities disclosed. In the drawings:
[0013] Figure 1 is a diagram of an exemplary metering system;
[0014] Figure 2 expands upon the diagram of Fig. 1 and illustrates an
exemplary metering
system in greater detail;
[0015] Figure 3A is a block diagram illustrating an exemplary collector;
[0016] Figure 3B is a block diagram illustrating an exemplary meter;
[0017] Figure 4 is a diagram of an example subnet of a wireless network for
collecting data
from remote devices;
[0018] Figure 5 is a diagram of an example system for hybrid employment of
fixed network
and mobile network communications according to an embodiment;
[0019] Figure 6 is a process flow diagram illustrating an example method for
consolidated data
collection;
[0020] Figure 7 is a diagram illustrating an example user interface for a
mobile data collection
device;
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[0021] Figure 8 is a diagram illustrating an example user interface for
collecting data from
endpoint devices identified by their serial number and encoded status
information;
[0022] Figure 9 is a diagram illustrating an example user interface for
displaying geographic
and other data associated with a particular endpoint device; and
[0023] Figure 10 is a diagram illustrating an example user interface for
displaying packet
performance and other data associated with a particular endpoint device.
DETAILED DESCRIPTION
[0024] Exemplary systems and methods for gathering meter data are described
below with
reference to Figures 1-10. It will be appreciated by those of ordinary skill
in the art that the
description given herein with respect to those figures is for exemplary
purposes only and is not
intended in any way to limit the scope of potential embodiments.
[0025] Generally, a plurality of meter devices, which operate to track usage
of a service or
commodity such as, for example, electricity, water, and gas, are operable to
wirelessly
communicate. One or more devices, referred to herein as "collectors," are
provided that "collect"
data transmitted by the other meter devices so that it can be accessed by
other computer systems.
The collectors receive and compile metering data from a plurality of meter
devices via wireless
communications. A data collection server may communicate with the collectors
to retrieve the
compiled meter data.
[0026] Figure 1 provides a diagram of one exemplary metering system 110.
System 110
comprises a plurality of meters 114, which are operable to sense and record
consumption or
usage of a service or commodity such as, for example, electricity, water, or
gas. Meters 114 may
be located at customer premises such as, for example, a home or place of
business. Meters 114
comprise circuitry for measuring the consumption of the service or commodity
being consumed
at their respective locations and for generating data reflecting the
consumption, as well as other
data related thereto. Meters 114 may also comprise circuitry for wirelessly
transmitting data
generated by the meter to a remote location. Meters 114 may further comprise
circuitry for
receiving data, commands or instructions wirelessly as well. Meters that are
operable to both
receive and transmit data may be referred to as "bi-directional" or "two-way"
meters, while
meters that are only capable of transmitting data may be referred to as
"transmit-only" or "one-
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way" meters. In bi-directional meters, the circuitry for transmitting and
receiving may comprise a
transceiver. In an illustrative embodiment, meters 114 may be, for example,
electricity meters
manufactured by Elster Solutions, LLC and marketed under the tradename REX.
[0027] System 110 further comprises collectors 116. In one embodiment,
collectors 116 are
also meters operable to detect and record usage of a service or commodity such
as, for example,
electricity, water, or gas. In addition, collectors 116 are operable to send
data to and receive data
from meters 114. Thus, like the meters 114, the collectors 116 may comprise
both circuitry for
measuring the consumption of a service or commodity and for generating data
reflecting the
consumption and circuitry for transmitting and receiving data. In one
embodiment, collector 116
and meters 114 communicate with and amongst one another using any one of
several wireless
techniques such as, for example, frequency hopping spread spectrum (FHSS) and
direct sequence
spread spectrum (DSSS).
[0028] A collector 116 and the meters 114 with which it communicates define a
subnet/LAN
120 of system 110. As used herein, meters 114 and collectors 116 may be
referred to as "nodes"
in the subnet 120. In each subnet/LAN 120, each meter transmits data related
to consumption of
the commodity being metered at the meter's location. The collector 116
receives the data
transmitted by each meter 114, effectively "collecting" it, and then
periodically transmits the
data from all of the meters in the subnet/LAN 120 to a data collection server
206. The data
collection server 206 stores the data for analysis and preparation of bills,
for example. The data
collection server 206 may be a specially programmed general purpose computing
system and
may communicate with collectors 116 via a network 112. The network 112 may
comprise any
form of network, including a wireless network or a fixed-wire network, such as
a local area
network (LAN), a wide area network, the Internet, an intranet, a telephone
network, such as the
public switched telephone network (PSTN), a Frequency Hopping Spread Spectrum
(FHSS)
radio network, a mesh network, a Wi-Fi (802.11) network, a Wi-Max (802.16)
network, a land
line (POTS) network, or any combination of the above.
100291 Referring now to Figure 2, further details of the metering system 110
are shown.
Typically, the system will be operated by a utility company or a company
providing information
technology services to a utility company. As shown, the system 110 comprises a
network
management server 202, a network management system (NMS) 204 and the data
collection
server 206 that together manage one or more subnets/LANs 120 and their
constituent nodes. The
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NMS 204 tracks changes in network state, such as new nodes
registering/unregistering with the
system 110, node communication paths changing, etc. This information is
collected for each
subnet/LAN 120 and is detected and forwarded to the network management server
202 and data
collection server 206.
[0030] Each of the meters 114 and collectors 116 is assigned an identifier
(LAN 113) that
uniquely identifies that meter or collector on its subnet/LAN 120. In this
embodiment,
communication between nodes (i.e., the collectors and meters) and the system
110 is
accomplished using the LAN ID. However, it is preferable for operators of a
utility to query and
communicate with the nodes using their own identifiers. To this end, a
marriage file 208 may be
used to correlate a utility's identifier for a node (e.g., a utility serial
number) with both a
manufacturer serial number (i.e., a serial number assigned by the manufacturer
of the meter) and
the LAN ID for each node in the subnet/LAN 120. In this manner, the utility
can refer to the
meters and collectors by the utilities identifier, while the system can employ
the LAN ID for the
purpose of designating particular meters during system communications.
100311 A device configuration database 210 stores configuration information
regarding the
nodes. For example, in the metering system 200, the device configuration
database may include
data regarding time of use (TOU) switchpoints, etc. for the meters 114 and
collectors 116
communicating in the system 110. A data collection requirements database 212
contains
information regarding the data to be collected on a per node basis. For
example, a utility may
specify that metering data such as load profile, demand, TOU, etc. is to be
collected from
particular meter(s) 114a. Reports 214 containing information on the network
configuration may
be automatically generated or in accordance with a utility request.
100321 The network management system (NMS) 204 maintains a database describing
the
current state of the global fixed network system (current network state 220)
and a database
describing the historical state of the system (historical network state 222).
The current network
state 220 contains data regarding current meter-to-collector assignments, etc.
for each
subnet/LAN 120. The historical network state 222 is a database from which the
state of the
network at a particular point in the past can be reconstructed. The NMS 204 is
responsible for,
amongst other things, providing reports 214 about the state of the network.
The NMS 204 may
be accessed via an API 220 that is exposed to a user interface 216 and a
Customer Information
System (CIS) 218. Other external interfaces may also be implemented. In
addition, the data
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collection requirements stored in the database 212 may be set via the user
interface 216 or CIS
218.
[0033] The data collection server 206 collects data from the nodes (e.g.,
collectors 116) and
stores the data in a database 224. The data includes metering information,
such as energy
consumption and may be used for billing purposes, etc. by a utility provider.
[0034] The network management server 202, network management system 204 and
data
collection server 206 communicate with the nodes in each subnet/LAN 120 via
network 110.
[0035] Figure 3A is a block diagram illustrating further details of one
embodiment of a
collector 116. Although certain components are designated and discussed with
reference to
Figure 3A, it should be appreciated that the invention is not limited to such
components. In fact,
various other components typically found in an electronic meter may be a part
of collector 116,
but have not been shown in Figure 3A for the purposes of clarity and brevity.
Also, the invention
may use other components to accomplish the operation of collector 116. The
components that are
shown and the functionality described for collector 116 are provided as
examples, and are not
meant to be exclusive of other components or other functionality.
[0036] As shown in Figure 3A, collector 116 may comprise metering circuitry
304 that
performs measurement of consumption of a service or commodity and a processor
305 that
controls the overall operation of the metering functions of the collector 116.
The collector 116
may further comprise a display 310 for displaying information such as measured
quantities and
meter status and a memory 312 for storing data. The collector 116 further
comprises wireless
LAN communications circuitry 306 for communicating wirelessly with the meters
114 in a
subnet/LAN and a network interface 308 for communication over the network 112.
[0037] In one embodiment, the metering circuitry 304, processor 305, display
310 and memory
312 are implemented using an A3 ALPHA meter available from Elster Solutions,
LLC. In that
embodiment, the wireless LAN communications circuitry 306 may be implemented
by a LAN
Option Board (e.g., a 900 MHz two-way radio) installed within the A3 ALPHA
meter, and the
network interface 308 may be implemented by a WAN Option Board (e.g., a
telephone modem)
also installed within the A3 ALPHA meter. In this embodiment, the WAN Option
Board 308
routes messages from network 112 (via interface port 302) to either the meter
processor 305 or
the LAN Option Board 306. LAN Option Board 306 may use a transceiver (not
shown), for
example a 900 MHz radio, to communicate data to meters 114. Also, LAN Option
Board 306
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may have sufficient memory to store data received from meters 114. This data
may include, but
is not limited to the following: current billing data (e.g., the present
values stored and displayed
by meters 114), previous billing period data, previous season data, and load
profile data.
[0038] LAN Option Board 306 may be capable of synchronizing its time to a real
time clock
(not shown) in A3 ALPHA meter, thereby synchronizing the LAN reference time to
the time in
the meter. The processing necessary to carry out the communication
functionality and the
collection and storage of metering data of the collector 116 may be handled by
the processor 305
and/or additional processors (not shown) in the LAN Option Board 306 and the
WAN Option
Board 308.
[0039] The responsibility of a collector 116 is wide and varied. Generally,
collector 116 is
responsible for managing, processing and routing data communicated between the
collector and
network 112 and between the collector and meters 114. Collector 116 may
continually or
intermittently read the current data from meters 114 and store the data in a
database (not shown)
in collector 116. Such current data may include but is not limited to the
total kWh usage, the
Time-Of-Use (TOU) kWh usage, peak kW demand, and other energy consumption
measurements and status information. Collector 116 also may read and store
previous billing and
previous season data from meters 114 and store the data in the database in
collector 116. The
database may be implemented as one or more tables of data within the collector
116.
[0040] Figure 3B is a block diagram of an exemplary embodiment of a meter 114
that may
operate in the system 110 of Figures 1 and 2. As shown, the meter 114
comprises metering
circuitry 304' for measuring the amount of a service or commodity that is
consumed, a processor
305' that controls the overall functions of the meter, a display 310' for
displaying meter data and
status information, and a memory 312' for storing data and program
instructions. The meter 114
further comprises wireless communications circuitry 306' for transmitting and
receiving data
to/from other meters 114 or a collector 116.
[0041] Referring again to Figure 1, in the exemplary embodiment shown, a
collector 116
directly communicates with only a subset of the plurality of meters 114 in its
particular
subnet/LAN. Meters 114 with which collector 116 directly communicates may be
referred to as
"level one" meters 114a. The level one meters 114a are said to be one "hop"
from the collector
116. Communications between collector 116 and meters 114 other than level one
meters 114a
are relayed through the level one meters 114a. Thus, the level one meters 114a
operate as
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repeaters for communications between collector 116 and meters 114 located
further away in
subnet 120.
[0042] Each level one meter 114a typically will only be in range to directly
communicate with
only a subset of the remaining meters 114 in the subnet 120. The meters 114
with which the level
one meters 114a directly communicate may be referred to as level two meters
114b. Level two
meters 114b are one "hop" from level one meters 114a, and therefore two "hops"
from collector
116. Level two meters 114b operate as repeaters for communications between the
level one
meters 114a and meters 114 located further away from collector 116 in the
subnet 120.
[0043] While only three levels of meters are shown (collector 116, first level
114a, second
level 114b) in Figure 1, a subnet 120 may comprise any number of levels of
meters 114. For
example, a subnet 120 may comprise one level of meters but might also comprise
eight or more
levels of meters 114. In an embodiment wherein a subnet comprises eight levels
of meters 114,
as many as 1024 meters might be registered with a single collector 116.
[0044] As mentioned above, each meter 114 and collector 116 that is installed
in the system
110 has a unique identifier (LAN ID) stored thereon that uniquely identifies
the device from all
other devices in the system 110. Additionally, meters 114 operating in a
subnet 120 comprise
information including the following: data identifying the collector with which
the meter is
registered; the level in the subnet at which the meter is located; the
repeater meter at the prior
level with which the meter communicates to send and receive data to/from the
collector; an
identifier indicating whether the meter is a repeater for other nodes in the
subnet; and if the meter
operates as a repeater, the identifier that uniquely identifies the repeater
within the particular
subnet, and the number of meters for which it is a repeater. Collectors 116
have stored thereon
all of this same data for all meters 114 that are registered therewith. Thus,
collector 116
comprises data identifying all nodes registered therewith as well as data
identifying the
registered path by which data is communicated from the collector to each node.
Each meter 114
therefore has a designated communications path to the collector that is either
a direct path (e.g.,
all level one nodes) or an indirect path through one or more intermediate
nodes that serve as
repeaters.
[0045] Information is transmitted in this embodiment in the form of packets.
For most network
tasks such as, for example, reading meter data, collector 116 communicates
with meters 114 in
the subnet 120 using point-to-point transmissions. For example, a message or
instruction from
CA 02831119 2013-10-23
collector 116 is routed through the designated set of repeaters to the desired
meter 114.
Similarly, a meter 114 communicates with collector 116 through the same set of
repeaters, but in
reverse.
[0046] In some instances, however, collector 116 may need to quickly
communicate
information to all meters 114 located in its subnet 120. Accordingly,
collector 116 may issue a
broadcast message that is meant to reach all nodes in the subnet 120. The
broadcast message may
be referred to as a "flood broadcast message." A flood broadcast originates at
collector 116 and
propagates through the entire subnet 120 one level at a time. For example,
collector 116 may
transmit a flood broadcast to all first level meters 114a. The first level
meters 114a that receive
the message pick a random time slot and retransmit the broadcast message to
second level meters
114b. Any second level meter 114b can accept the broadcast, thereby providing
better coverage
from the collector out to the end point meters. Similarly, the second level
meters 114b that
receive the broadcast message pick a random time slot and communicate the
broadcast message
to third level meters. This process continues out until the end nodes of the
subnet. Thus, a
broadcast message gradually propagates outward from the collector to the nodes
of the subnet
120.
[0047] The flood broadcast packet header contains information to prevent nodes
from
repeating the flood broadcast packet more than once per level. For example,
within a flood
broadcast message, a field might exist that indicates to meters/nodes which
receive the message,
the level of the subnet the message is located; only nodes at that particular
level may re-
broadcast the message to the next level. If the collector broadcasts a flood
message with a level
of 1, only level 1 nodes may respond. Prior to re-broadcasting the flood
message, the level 1
nodes increment the field to 2 so that only level 2 nodes respond to the
broadcast. Information
within the flood broadcast packet header ensures that a flood broadcast will
eventually die out.
[0048] Generally, a collector 116 issues a flood broadcast several times, e.g.
five times,
successively to increase the probability that all meters in the subnet 120
receive the broadcast. A
delay is introduced before each new broadcast to allow the previous broadcast
packet time to
propagate through all levels of the subnet.
[0049] Meters 114 may have a clock formed therein. However, meters 114 often
undergo
power interruptions that can interfere with the operation of any clock
therein. Accordingly, the
clocks internal to meters 114 cannot be relied upon to provide an accurate
time reading. Having
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the correct time is necessary, however, when time of use metering is being
employed. Indeed, in
an embodiment, time of use schedule data may also be comprised in the same
broadcast message
as the time. Accordingly, collector 116 periodically flood broadcasts the real
time to meters 114
in subnet 120. Meters 114 use the time broadcasts to stay synchronized with
the rest of the
subnet 120. In an illustrative embodiment, collector 116 broadcasts the time
every 15 minutes.
The broadcasts may be made near the middle of 15 minute clock boundaries that
are used in
performing load profiling and time of use (TOU) schedules so as to minimize
time changes near
these boundaries. Maintaining time synchronization is important to the proper
operation of the
subnet 120. Accordingly, lower priority tasks performed by collector 116 may
be delayed while
the time broadcasts are performed.
[0050] In an illustrative embodiment, the flood broadcasts transmitting time
data may be
repeated, for example, five times, so as to increase the probability that all
nodes receive the time.
Furthermore, where time of use schedule data is communicated in the same
transmission as the
timing data, the subsequent time transmissions allow a different piece of the
time of use schedule
to be transmitted to the nodes.
[0051] Exception messages are used in subnet 120 to transmit unexpected events
that occur at
meters 114 to collector 116. In an embodiment, the first 4 seconds of every 32-
second period are
allocated as an exception window for meters 114 to transmit exception
messages. Meters 114
transmit their exception messages early enough in the exception window so the
message has time
to propagate to collector 116 before the end of the exception window.
Collector 116 may process
the exceptions after the 4-second exception window. Generally, a collector 116
acknowledges
exception messages, and collector 116 waits until the end of the exception
window to send this
acknowledgement.
[0052] In an illustrative embodiment, exception messages are configured as one
of three
different types of exception messages: local exceptions, which are handled
directly by the
collector 116 without intervention from data collection server 206; an
immediate exception,
which is generally relayed to data collection server 206 under an expedited
schedule; and a daily
exception, which is communicated to the communication server 122 on a regular
schedule.
[0053] Exceptions are processed as follows. When an exception is received at
collector 116,
the collector 116 identifies the type of exception that has been received. If
a local exception has
been received, collector 116 takes an action to remedy the problem. For
example, when collector
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116 receives an exception requesting a "node scan request" such as discussed
below, collector
116 transmits a command to initiate a scan procedure to the meter 114 from
which the exception
was received.
[0054] If an immediate exception type has been received, collector 116 makes a
record of the
exception. An immediate exception might identify, for example, that there has
been a power
outage. Collector 116 may log the receipt of the exception in one or more
tables or files. In an
illustrative example, a record of receipt of an immediate exception is made in
a table referred to
as the "Immediate Exception Log Table." Collector 116 then waits a set period
of time before
taking further action with respect to the immediate exception. For example,
collector 116 may
wait 64 seconds. This delay period allows the exception to be corrected before
communicating
the exception to the data collection server 206. For example, where a power
outage was the cause
of the immediate exception, collector 116 may wait a set period of time to
allow for receipt of a
message indicating the power outage has been corrected.
[0055] If the exception has not been corrected, collector 116 communicates the
immediate
exception to data collection server 206. For example, collector 116 may
initiate a dial-up
connection with data collection server 206 and download the exception data.
After reporting an
immediate exception to data collection server 206, collector 116 may delay
reporting any
additional immediate exceptions for a period of time such as ten minutes. This
is to avoid
reporting exceptions from other meters 114 that relate to, or have the same
cause as, the
exception that was just reported.
[0056] If a daily exception was received, the exception is recorded in a file
or a database table.
Generally, daily exceptions are occurrences in the subnet 120 that need to be
reported to data
collection server 206, but are not so urgent that they need to be communicated
immediately. For
example, when collector 116 registers a new meter 114 in subnet 120, collector
116 records a
daily exception identifying that the registration has taken place. In an
illustrative embodiment,
the exception is recorded in a database table referred to as the "Daily
Exception Log Table."
Collector 116 communicates the daily exceptions to data collection server 206.
Generally,
collector 116 communicates the daily exceptions once every 24 hours.
[0057] In the present embodiment, a collector assigns designated
communications paths to
meters with bi-directional communication capability, and may change the
communication paths
for previously registered meters if conditions warrant. For example, when a
collector 116 is
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initially brought into system 110, it needs to identify and register meters in
its subnet 120. A
"node scan" refers to a process of communication between a collector 116 and
meters 114
whereby the collector may identify and register new nodes in a subnet 120 and
allow previously
registered nodes to switch paths. A collector 116 can implement a node scan on
the entire subnet,
referred to as a "full node scan," or a node scan can be performed on
specially identified nodes,
referred to as a "node scan retry."
100581 A full node scan may be performed, for example, when a collector is
first installed. The
collector 116 must identify and register nodes from which it will collect
usage data. The collector
116 initiates a node scan by broadcasting a request, which may be referred to
as a Node Scan
Procedure request. Generally, the Node Scan Procedure request directs that all
unregistered
meters 114 or nodes that receive the request respond to the collector 116. The
request may
comprise information such as the unique address of the collector that
initiated the procedure. The
signal by which collector 116 transmits this request may have limited strength
and therefore is
detected only at meters 114 that are in proximity of collector 116. Meters 114
that receive the
Node Scan Procedure request respond by transmitting their unique identifier as
well as other
data.
100591 For each meter from which the collector receives a response to the Node
Scan
Procedure request, the collector tries to qualify the communications path to
that meter before
registering the meter with the collector. That is, before registering a meter,
the collector 116
attempts to determine whether data communications with the meter will be
sufficiently reliable.
In one embodiment, the collector 116 determines whether the communication path
to a
responding meter is sufficiently reliable by comparing a Received Signal
Strength Indication
(RSSI) value (i.e., a measurement of the received radio signal strength)
measured with respect to
the received response from the meter to a selected threshold value. For
example, the threshold
value may be ¨60 dBm. RSSI values above this threshold would be deemed
sufficiently reliable.
In another embodiment, qualification is performed by transmitting a
predetermined number of
additional packets to the meter, such as ten packets, and counting the number
of
acknowledgements received back from the meter. If the number of
acknowledgments received is
greater than or equal to a selected threshold (e.g., 8 out of 10), then the
path is considered to be
reliable. In other embodiments, a combination of the two qualification
techniques may be
employed.
14
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[0060] If the qualification threshold is not met, the collector 116 may add an
entry for the
meter to a "Straggler Table." The entry includes the meter's LAN ID, its
qualification score (e.g.,
out of 10; or its RSSI value), its level (in this case level one) and the
unique ID of its parent (in
this case the collector's ID).
[0061] If the qualification threshold is met or exceeded, the collector 116
registers the node.
Registering a meter 114 comprises updating a list of the registered nodes at
collector 116. For
example, the list may be updated to identify the meter's system-wide unique
identifier and the
communication path to the node. Collector 116 also records the meter's level
in the subnet (i.e.
whether the meter is a level one node, level two node, etc.), whether the node
operates as a
repeater, and if so, the number of meters for which it operates as a repeater.
The registration
process further comprises transmitting registration information to the meter
114. For example,
collector 116 forwards to meter 114 an indication that it is registered, the
unique identifier of the
collector with which it is registered, the level the meter exists at in the
subnet, and the unique
identifier of its parent meter that will serve as a repeater for messages the
meter may send to the
collector. In the case of a level one node, the parent is the collector
itself. The meter stores this
data and begins to operate as part of the subnet by responding to commands
from its collector
116.
[0062] Qualification and registration continues for each meter that responds
to the collector's
initial Node Scan Procedure request. The collector 116 may rebroadcast the
Node Scan
Procedure additional times so as to insure that all meters 114 that may
receive the Node Scan
Procedure have an opportunity for their response to be received and the meter
qualified as a level
one node at collector 116.
[0063] The node scan process then continues by performing a similar process as
that described
above at each of the now registered level one nodes. This process results in
the identification and
registration of level two nodes. After the level two nodes are identified, a
similar node scan
process is performed at the level two nodes to identify level three nodes, and
so on.
[0064] Specifically, to identify and register meters that will become level
two meters, for each
level one meter, in succession, the collector 116 transmits a command to the
level one meter,
which may be referred to as an "Initiate Node Scan Procedure" command. This
command
instructs the level one meter to perform its own node scan process. The
request comprises several
data items that the receiving meter may use in completing the node scan. For
example, the
CA 02831119 2013-10-23
request may comprise the number of timeslots available for responding nodes,
the unique address
of the collector that initiated the request, and a measure of the reliability
of the communications
between the target node and the collector. As described below, the measure of
reliability may be
employed during a process for identifying more reliable paths for previously
registered nodes.
[0065] The meter that receives the Initiate Node Scan Response request
responds by
performing a node scan process similar to that described above. More
specifically, the meter
broadcasts a request to which all unregistered nodes may respond. The request
comprises the
number of timeslots available for responding nodes (which is used to set the
period for the node
to wait for responses), the unique address of the collector that initiated the
node scan procedure,
a measure of the reliability of the communications between the sending node
and the collector
(which may be used in the process of determining whether a meter's path may be
switched as
described below), the level within the subnet of the node sending the request,
and an RSSI
threshold (which may also be used in the process of determining whether a
registered meter's
path may be switched). The meter issuing the node scan request then waits for
and receives
responses from unregistered nodes. For each response, the meter stores in
memory the unique
identifier of the responding meter. This information is then transmitted to
the collector.
[0066] For each unregistered meter that responded to the node scan issued by
the level one
meter, the collector attempts again to determine the reliability of the
communication path to that
meter. In one embodiment, the collector sends a "Qualify Nodes Procedure"
command to the
level one node which instructs the level one node to transmit a predetermined
number of
additional packets to the potential level two node and to record the number of
acknowledgements
received back from the potential level two node. This qualification score
(e.g., 8 out of 10) is
then transmitted back to the collector, which again compares the score to a
qualification
threshold. In other embodiments, other measures of the communications
reliability may be
provided, such as an RSSI value.
[0067] If the qualification threshold is not met, then the collector adds an
entry for the node in
the Straggler Table, as discussed above. However, if there already is an entry
in the Straggler
Table for the node, the collector will update that entry only if the
qualification score for this node
scan procedure is better than the recorded qualification score from the prior
node scan that
resulted in an entry for the node.
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100681 If the qualification threshold is met or exceeded, the collector 116
registers the node.
Again, registering a meter 114 at level two comprises updating a list of the
registered nodes at
collector 116. For example, the list may be updated to identify the meter's
unique identifier and
the level of the meter in the subnet. Additionally, the collector's 116
registration information is
updated to reflect that the meter 114 from which the scan process was
initiated is identified as a
repeater (or parent) for the newly registered node. The registration process
further comprises
transmitting information to the newly registered meter as well as the meter
that will serve as a
repeater for the newly added node. For example, the node that issued the node
scan response
request is updated to identify that it operates as a repeater and, if it was
previously registered as a
repeater, increments a data item identifying the number of nodes for which it
serves as a repeater.
Thereafter, collector 116 forwards to the newly registered meter an indication
that it is registered,
an identification of the collector 116 with which it is registered, the level
the meter exists at in
the subnet, and the unique identifier of the node that will serve as its
parent, or repeater, when it
communicates with the collector 116.
100691 The collector then performs the same qualification procedure for each
other potential
level two node that responded to the level one node's node scan request. Once
that process is
completed for the first level one node, the collector initiates the same
procedure at each other
level one node until the process of qualifying and registering level two nodes
has been completed
at each level one node. Once the node scan procedure has been performed by
each level one
node, resulting in a number of level two nodes being registered with the
collector, the collector
will then send the Initiate Node Scan Response command to each level two node,
in turn. Each
level two node will then perform the same node scan procedure as performed by
the level one
nodes, potentially resulting in the registration of a number of level three
nodes. The process is
then performed at each successive node, until a maximum number of levels is
reached (e.g.,
seven levels) or no unregistered nodes are left in the subnet.
100701 It will be appreciated that in the present embodiment, during the
qualification process
for a given node at a given level, the collector qualifies the last "hop"
only. For example, if an
unregistered node responds to a node scan request from a level four node, and
therefore,
becomes a potential level five node, the qualification score for that node is
based on the
reliability of communications between the level four node and the potential
level five node (i.e.,
packets transmitted by the level four node versus acknowledgments received
from the potential
17
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level five node), not based on any measure of the reliability of the
communications over the full
path from the collector to the potential level five node. In other
embodiments, of course, the
qualification score could be based on the full communication path.
100711 At some point, each meter will have an established communication path
to the collector
which will be either a direct path (i.e., level one nodes) or an indirect path
through one or more
intermediate nodes that serve as repeaters. If during operation of the
network, a meter registered
in this manner fails to perform adequately, it may be assigned a different
path or possibly to a
different collector as described below.
100721 As previously mentioned, a full node scan may be performed when a
collector 116 is
first introduced to a network. At the conclusion of the full node scan, a
collector 116 will have
registered a set of meters 114 with which it communicates and reads metering
data. Full node
scans might be periodically performed by an installed collector to identify
new meters 114 that
have been brought on-line since the last node scan and to allow registered
meters to switch to a
different path.
[00731 In addition to the full node scan, collector 116 may also perform a
process of scanning
specific meters 114 in the subnet 120, which is referred to as a "node scan
retry." For example,
collector 116 may issue a specific request to a meter 114 to perform a node
scan outside of a full
node scan when on a previous attempt to scan the node, the collector 116 was
unable to confirm
that the particular meter 114 received the node scan request. Also, a
collector 116 may request a
node scan retry of a meter 114 when during the course of a full node scan the
collector 116 was
unable to read the node scan data from the meter 114. Similarly, a node scan
retry will be
performed when an exception procedure requesting an immediate node scan is
received from a
meter 114.
100741 The system 110 also automatically reconfigures to accommodate a new
meter 114 that
may be added. More particularly, the system identifies that the new meter has
begun operating
and identifies a path to a collector 116 that will become responsible for
collecting the metering
data. Specifically, the new meter will broadcast an indication that it is
unregistered. In one
embodiment, this broadcast might be, for example, embedded in, or relayed as
part of a request
for an update of the real time as described above. The broadcast will be
received at one of the
registered meters 114 in proximity to the meter that is attempting to
register. The registered
meter 114 forwards the time to the meter that is attempting to register. The
registered node also
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CA 02831119 2013-10-23
transmits an exception request to its collector 116 requesting that the
collector 116 implement a
node scan, which presumably will locate and register the new meter. The
collector 116 then
transmits a request that the registered node perform a node scan. The
registered node will
perform the node scan, during which it requests that all unregistered nodes
respond. Presumably,
the newly added, unregistered meter will respond to the node scan. When it
does, the collector
will then attempt to qualify and then register the new node in the same manner
as described
above.
[0075] Once a communication path between the collector and a meter is
established, the meter
can begin transmitting its meter data to the collector and the collector can
transmit data and
instructions to the meter. As mentioned above, data is transmitted in packets.
"Outbound"
packets are packets transmitted from the collector to a meter at a given
level. In one embodiment,
outbound packets contain the following fields, but other fields may also be
included:
Length ¨ the length of the packet;
SrcAddr ¨ source address ¨ in this case, the ID of the collector;
DestAddr ¨ the LAN ID of the meter to which the packet addressed;
RptPath ¨ the communication path to the destination meter (i.e., the list of
identifiers of each
repeater in the path from the collector to the destination node); and
Data ¨ the payload of the packet.
The packet may also include integrity check information (e.g., CRC), a pad to
fill-out unused
portions of the packet and other control information. When the packet is
transmitted from the
collector, it will only be forwarded on to the destination meter by those
repeater meters whose
identifiers appear in the RptPath field. Other meters that may receive the
packet, but that are not
listed in the path identified in the RptPath field will not repeat the packet.
[0076] "Inbound" packets are packets transmitted from a meter at a given level
to the collector.
In one embodiment, inbound packets contain the following fields, but other
fields may also be
included:
Length ¨ the length of the packet;
SrcAddr ¨ source address ¨ the address of the meter that initiated the packet;
DestAddr ¨ the ID of the collector to which the packet is to be transmitted;
RptAddr ¨ the ID of the parent node that serves as the next repeater for the
sending node;
Data ¨ the payload of the packet;
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Because each meter knows the identifier of its parent node (i.e., the node in
the next lower level
that serves as a repeater for the present node), an inbound packet need only
identify who is the
next parent. When a node receives an inbound packet, it checks to see if the
RptAddr matches its
own identifier. If not, it discards the packet. If so, it knows that it is
supposed to forward the
packet on toward the collector. The node will then replace the RptAddr field
with the identifier
of its own parent and will then transmit the packet so that its parent will
receive it. This process
will continue through each repeater at each successive level until the packet
reaches the
collector.
[0077] For example, suppose a meter at level three initiates transmission of a
packet destined
for its collector. The level three node will insert in the RptAddr field of
the inbound packet the
identifier of the level two node that serves as a repeater for the level three
node. The level three
node will then transmit the packet. Several level two nodes may receive the
packet, but only the
level two node having an identifier that matches the identifier in the RptAddr
field of the packet
will acknowledge it. The other will discard it. When the level two node with
the matching
identifier receives the packet, it will replace the RptAddr field of the
packet with the identifier of
the level one packet that serves as a repeater for that level two packet, and
the level two packet
will then transmit the packet. This time, the level one node having the
identifier that matches the
RptAddr field will receive the packet. The level one node will insert the
identifier of the collector
in the RptAddr field and will transmit the packet. The collector will then
receive the packet to
complete the transmission.
[0078] A collector 116 periodically retrieves meter data from the meters that
are registered
with it. For example, meter data may be retrieved from a meter every 4 hours.
Where there is a
problem with reading the meter data on the regularly scheduled interval, the
collector will try to
read the data again before the next regularly scheduled interval.
Nevertheless, there may be
instances wherein the collector 116 is unable to read metering data from a
particular meter 114
for a prolonged period of time. The meters 114 store an indication of when
they are read by their
collector 116 and keep track of the time since their data has last been
collected by the collector
116. If the length of time since the last reading exceeds a defined threshold,
such as for example,
18 hours, presumably a problem has arisen in the communication path between
the particular
meter 114 and the collector 116. Accordingly, the meter 114 changes its status
to that of an
unregistered meter and attempts to locate a new path to a collector 116 via
the process described
CA 02831119 2013-10-23
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above for a new node. Thus, the exemplary system is operable to reconfigure
itself to address
inadequacies in the system.
[0079] In some instances, while a collector 116 may be able to retrieve data
from a registered
meter 114 occasionally, the level of success in reading the meter may be
inadequate. For
example, if a collector 116 attempts to read meter data from a meter 114 every
4 hours but is able
to read the data, for example, only 70 percent of the time or less, it may be
desirable to find a
more reliable path for reading the data from that particular meter. Where the
frequency of
reading data from a meter 114 falls below a desired success level, the
collector 116 transmits a
message to the meter 114 to respond to node scans going forward. The meter 114
remains
registered but will respond to node scans in the same manner as an
unregistered node as
described above. In other embodiments, all registered meters may be permitted
to respond to
node scans, but a meter will only respond to a node scan if the path to the
collector through the
meter that issued the node scan is shorter (i.e., less hops) than the meter's
current path to the
collector. A lesser number of hops is assumed to provide a more reliable
communication path
than a longer path. A node scan request always identifies the level of the
node that transmits the
request, and using that information, an already registered node that is
permitted to respond to
node scans can determine if a potential new path to the collector through the
node that issued the
node scan is shorter than the node's current path to the collector.
[0080] If an already registered meter 114 responds to a node scan procedure,
the collector 116
recognizes the response as originating from a registered meter but that by re-
registering the meter
with the node that issued the node scan, the collector may be able to switch
the meter to a new,
more reliable path. The collector 116 may verify that the RSSI value of the
node scan response
exceeds an established threshold. If it does not, the potential new path will
be rejected. However,
if the RSSI threshold is met, the collector 116 will request that the node
that issued the node scan
perform the qualification process described above (i.e., send a predetermined
number of packets
to the node and count the number of acknowledgements received). If the
resulting qualification
score satisfies a threshold, then the collector will register the node with
the new path. The
registration process comprises updating the collector 116 and meter 114 with
data identifying the
new repeater (i.e. the node that issued the node scan) with which the updated
node will now
communicate. Additionally, if the repeater has not previously performed the
operation of a
repeater, the repeater would need to be updated to identify that it is a
repeater. Likewise, the
21
CA 02831119 2013-10-23
repeater with which the meter previously communicated is updated to identify
that it is no longer
a repeater for the particular meter 114. In other embodiments, the threshold
determination with
respect to the RSSI value may be omitted. In such embodiments, only the
qualification of the last
"hop" (i.e., sending a predetermined number of packets to the node and
counting the number of
acknowledgements received) will be performed to determine whether to accept or
reject the new
path.
100811 In some instances, a more reliable communication path for a meter may
exist through a
collector other than that with which the meter is registered. A meter may
automatically recognize
the existence of the more reliable communication path, switch collectors, and
notify the previous
collector that the change has taken place. The process of switching the
registration of a meter
from a first collector to a second collector begins when a registered meter
114 receives a node
scan request from a collector 116 other than the one with which the meter is
presently registered.
Typically, a registered meter 114 does not respond to node scan requests.
However, if the request
is likely to result in a more reliable transmission path, even a registered
meter may respond.
Accordingly, the meter determines if the new collector offers a potentially
more reliable
transmission path. For example, the meter 114 may determine if the path to the
potential new
collector 116 comprises fewer hops than the path to the collector with which
the meter is
registered. If not, the path may not be more reliable and the meter 114 will
not respond to the
node scan. The meter 114 might also determine if the RSSI of the node scan
packet exceeds an
RSSI threshold identified in the node scan information. If so, the new
collector may offer a more
reliable transmission path for meter data. If not, the transmission path may
not be acceptable and
the meter may not respond. Additionally, if the reliability of communication
between the
potential new collector and the repeater that would service the meter meets a
threshold
established when the repeater was registered with its existing collector, the
communication path
to the new collector may be more reliable. If the reliability does not exceed
this threshold,
however, the meter 114 does not respond to the node scan.
100821 If it is determined that the path to the new collector may be better
than the path to its
existing collector, the meter 114 responds to the node scan. Included in the
response is
information regarding any nodes for which the particular meter may operate as
a repeater. For
example, the response might identify the number of nodes for which the meter
serves as a
repeater.
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100831 The collector 116 then determines if it has the capacity to service the
meter and any
meters for which it operates as a repeater. If not, the collector 116 does not
respond to the meter
that is attempting to change collectors. If, however, the collector 116
determines that it has
capacity to service the meter 114, the collector 116 stores registration
information about the
meter 114. The collector 116 then transmits a registration command to meter
114. The meter 114
updates its registration data to identify that it is now registered with the
new collector. The
collector 116 then communicates instructions to the meter 114 to initiate a
node scan request.
Nodes that are unregistered, or that had previously used meter 114 as a
repeater respond to the
request to identify themselves to collector 116. The collector registers these
nodes as is described
above in connection with registering new meters/nodes.
[0084J Under some circumstances it may be necessary to change a collector. For
example, a
collector may be malfunctioning and need to be taken off-line. Accordingly, a
new
communication path must be provided for collecting meter data from the meters
serviced by the
particular collector. The process of replacing a collector is performed by
broadcasting a message
to unregister, usually from a replacement collector, to all of the meters that
are registered with
the collector that is being removed from service. In one embodiment,
registered meters may be
programmed to only respond to commands from the collector with which they are
registered.
Accordingly, the command to unregister may comprise the unique identifier of
the collector that
is being replaced. In response to the command to unregister, the meters begin
to operate as
unregistered meters and respond to node scan requests. To allow the
unregistered command to
propagate through the subnet, when a node receives the command it will not
unregister
immediately, but rather remain registered for a defined period, which may be
referred to as the
"Time to Live." During this time to live period, the nodes continue to respond
to application
layer and immediate retries allowing the unregistration command to propagate
to all nodes in the
subnet. Ultimately, the meters register with the replacement collector using
the procedure
described above.
[00851 One of collector's 116 main responsibilities within subnet 120 is to
retrieve metering
data from meters 114. In one embodiment, collector 116 has as a goal to obtain
at least one
successful read of the metering data per day from each node in its subnet.
Collector 116 attempts
to retrieve the data from all nodes in its subnet 120 at a configurable
periodicity. For example,
collector 116 may be configured to attempt to retrieve metering data from
meters 114 in its
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CA 02831119 2013-10-23
subnet 120 once every 4 hours. In greater detail, in one embodiment, the data
collection process
begins with the collector 116 identifying one of the meters 114 in its subnet
120. For example,
collector 116 may review a list of registered nodes and identify one for
reading. The collector
116 then communicates a command to the particular meter 114 that it forward
its metering data
to the collector 116. If the meter reading is successful and the data is
received at collector 116,
the collector 116 determines if there are other meters that have not been read
during the present
reading session. If so, processing continues. However, if all of the meters
114 in subnet 120 have
been read, the collector waits a defined length of time, such as, for example,
4 hours, before
attempting another read.
10086] If during a read of a particular meter, the meter data is not received
at collector 116, the
collector 116 begins a retry procedure wherein it attempts to retry the data
read from the
particular meter. Collector 116 continues to attempt to read the data from the
node until either
the data is read or the next subnet reading takes place. In an embodiment,
collector 116 attempts
to read the data every 60 minutes. Thus, wherein a subnet reading is taken
every 4 hours,
collector 116 may issue three retries between subnet readings.
10087] Meters 114 are often two-way meters ¨ i.e. they are operable to both
receive and
transmit data. However, one-way meters that are operable only to transmit and
not receive data
may also be deployed. Figure 4 is a block diagram illustrating a subnet 401
that includes a
number of one-way meters 451-456. As shown, meters 114a-k are two-way devices.
In this
example, the two-way meters 114a-k operate in the exemplary manner described
above, such
that each meter has a communication path to the collector 116 that is either a
direct path (e.g.,
meters 114a and 114b have a direct path to the collector 116) or an indirect
path through one or
more intermediate meters that serve as repeaters. For example, meter 114h has
a path to the
collector through, in sequence, intermediate meters 114d and 114b. 1n this
example embodiment,
when a one-way meter (e.g., meter 451) broadcasts its usage data, the data may
be received at
one or more two-way meters that are in proximity to the one-way meter (e.g.,
two-way meters
114f and 114g). In one embodiment, the data from the one-way meter is stored
in each two-way
meter that receives it, and the data is designated in those two-way meters as
having been
received from the one-way meter. At some point, the data from the one-way
meter is
communicated, by each two-way meter that received it, to the collector 116.
For example, when
the collector reads the two-way meter data, it recognizes the existence of
meter data from the
24
CA 02831119 2013-10-23
one-way meter and reads it as well. After the data from the one-way meter has
been read, it is
removed from memory.
[0088] While the collection of data from one-way meters by the collector has
been described
above in the context of a network of two-way meters 114 that operate in the
manner described in
connection with the embodiments described above, it is understood that the
present invention is
not limited to the particular form of network established and utilized by the
meters 114 to
transmit data to the collector. Rather, the present invention may be used in
the context of any
network topology in which a plurality of two-way communication nodes are
capable of
transmitting data and of having that data propagated through the network of
nodes to the
collector.
[0089] According to various embodiments, the capabilities of a mobile
interrogator can be
enhanced. As a result, the performance of both fixed and mobile networks can
be improved. In
addition, a hybrid system can be realized that provides a utility company with
advantages of both
fixed and mobile networks.
[0090] In one embodiment, a mobile interrogator can be used to improve the
performance and
reliability of mobile, fixed, and hybrid meter reading and utility networks. A
fixed network
typically has a tree structure with endpoint devices or units at the extreme
ends of the tree.
These endpoint devices relay their data toward a central head end by passing
data first through
a local area network (LAN) that includes other endpoint devices, repeaters,
and collectors, and
then through a wide area network (WAN) to the head end. Many of the endpoint
devices
or units, such as electric meters, are always on. Other endpoint devices or
units, however, are
battery operated, such as sleepy gas, water, and in-home modules. Such devices
use a periodic
wake up methodology in order to tie into the network. This periodic wake up
process can be
unilateral at the discretion of the endpoint or the result of some wake up
process initiated by
adjacent always-on devices.
[0091] Figure 5 illustrates an example system 500 for hybrid employment of
fixed network
and mobile network communications according to an embodiment. The system 500
includes a
plurality of communication nodes, some of which are fixed network mode devices
502 and
others of which are mobile mode devices 510. As set forth above, the fixed
network mode
devices 502 may include, for example, any combination of meters, repeaters,
collectors,
gateways and other devices. As also set forth above, the fixed network mode
devices 502 may
CA 02831119 2013-10-23
=
communicate using one or more fixed wireless network communication protocols,
such as, for
example, a local area network (LAN) protocol and/or a wide area network (WAN)
protocol. The
fixed network mode devices 502 may also communicate using respective fixed
transmission
paths 504 and may employ, for example, Advanced Metering Infrastructure (AMI)
techniques.
[0092] At least some other of the communication nodes are mobile mode devices
510 that
operate in a mobile mode in which they transmit meter data to a mobile device
508, such as a
mobile interrogator device, using one or more mobile communication protocols.
These mobile
mode devices 510 may, for example, communicate using Automatic Meter ReadiOg
(AMR)
techniques.
[0093] According to some exemplary embodiments, in addition to communicating
with mobile
mode devices 510, the mobile device 508 may communicate with one or more fixed
network
mode devices 502 using one or more fixed network communication protocols. The
mobile
device 508 may be referred to as a hybrid mobile interrogator device because
it can be used to
implement a hybrid network that combines features of fixed networks and mobile
networks.
Such a hybrid mobile interrogator may provide a number of advantages in
connection with both
traditional fixed and mobile systems as will be described in detail below.
[0094] One challenge for a fixed network is maintaining the underlying,
backbone
communication system, especially in times of outages, maintenance, equipment
failures or
fluctuating network topologies. These situations may cause loss of data at the
local nodes and
disrupt the communication paths, so that downstream data is prevented from
reaching the
head end. Accordingly, in times of stress (e.g., power outages) when the
backbone
communication system is most critically needed, the backbone communication
system may be
dysfunctional. Data and status from the nodes may have difficulty getting to
the head end, and
restoration/reconfiguration commands from the head end may not be able to get
out to the
nodes in need. In these times, and even during normal network reconfiguration
(controlled or
automated), islands of endpoints may become isolated, or "orphaned," and the
utility may
lack the information needed to efficiently restore the network.
[0095] A hybrid mobile interrogator device that has a variety of local area
network (LAN)
and wide area network (WAN) communication capabilities can fix or greatly
improve
these situations. For example, during times of maintenance, when a collector
or repeater is
not functional or is being serviced, the mobile device 508 can be put in
position and can
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CA 02831119 2013-10-23
substitute for the collector or repeater and allow the system to operate
unaffected by the
maintenance. In this function, the mobile device 508 can provide LAN and/or
WAN
communication channels.
[0096] As another example, during route-based data gathering, the mobile
device 508 can
use wake-up technology and/or passive reception that works for the battery
operated
endpoints in the fixed network, so that data can be gathered directly. This
allows data
collection in the absence of the always-on LAN devices (for example, electric
meters,
repeaters, or collectors).
[0097] The mobile device 508 can also be used to gather data from orphaned
endpoint
devices, including always on and battery operated devices, until the time they
reenter the
network. To expedite reentry of an orphaned endpoint device into the network,
the mobile
device 508 can command the orphaned endpoint device to communicate with a more
optimal connection point (e.g., a collector or repeater device), rather than
waiting for the
orphaned endpoint device to make this determination itself.
[0098] In some embodiments, the mobile device 508 can provide configuration
data to or
otherwise control the operation of fixed network mode devices 502. For
instance, the mobile
device 508 can direct endpoints to disassociate from one collector and move to
another collector
to balance loading in the network and relieve congestion. The mobile device
508 can also be
used to apply configuration and enable encryption and software upgrades to
specific regions of
a network, which may, for example, require special attention due to, for
example, weaknesses
in the WAN/LAN, special operating modes, or orphaned meters. As another
example, the
mobile device 508 can perform encryption key management under the direction of
a key
manager in the head end. The mobile device 508 can also apply other changes to
endpoints,
such as performing connect and disconnect operations. When the mobile device
508 gathers
data and effects changes, it may keep a log for audit trail purposes, and the
log may be
encrypted for security and to prevent tampering. In some cases, when the
mobile device 508
inserts itself into a fixed network, it may take on the "personality"
including, for example,
the LAN ID, behavior, and/or encryption method of one or more specific network
devices
so that the mobile device 508 is allowed to participate in the network.
[0099] The mobile device 508 can also aid in understanding and troubleshooting
the
performance of a fixed network by, for example, gathering connectivity data
from endpoints
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CA 02831119 2013-10-23
and determining which endpoints have contact with which other endpoints. If
certain nodes
are having communication issues, the mobile de vice 508 can travel a route
surrounding the
nodes and determine, for example, the RF signal quality and/or connectivity of
the nodes in
question by, for example, pinging them and measuring RF signal strength, e.g.,
a Received
Signal Strength Indicator (RSSI) value. In doing so, the mobile device 508 can
determine why
a node may be orphaned or have poor connectivity.
[0100] While some of the advantages of a "hybrid" mobile device in fixed
networks are
described above, such a device also offers advantages over traditional mobile
systems. A mobile
system can be drive-by, fly-by, or walk-by in nature. In a mobile system, a
mobile interrogator,
such as the mobile device 508 of Figure 5, travels a predetermined route, for
example, once a
month in order to gather data from and, if possible, issue commands to
endpoint devices in
residential and commercial locations. These endpoint devices may include, for
example, water,
gas, and electric metering and control devices (e.g., thermostats, and load
control). There is
typically little or no communication between the endpoint devices themselves,
and each
endpoint device may maintain its own history of data for a period, such as the
past month. In
some embodiments, the mobile device 508 may use a wake-up signal to wake up
the
endpoint devices for the communication exchange. Alternatively, the endpoint
devices may
unilaterally transmit their data periodically (e.g., every few seconds), so
that it can be heard
by the mobile device 508 whenever it travels by. The collected data is
eventually passed from
the mobile device 508, to a route manager, and then up to a head end that
interfaces to the
utility billing system.
[0101] One challenge for mobile systems is the time it takes to gather the
information from
the endpoint devices. The time that is required to travel all of the
geographically diverse routes
increases the quantity and cost of the resources, both in terms of people and
equipment, that
are required to gather the data. Travel speed can be increased and travel time
decreased if, for
example, the number of endpoint devices or modules that need to be woken up
decreases.
Travel time can also be decreased if the number of always-on devices that need
to be
contacted decreases. Travel speed can be increased if data exchanges are
performed more
efficiently, for example, by working with consolidated or processed data.
[0102] The capabilities of a mobile network can be increased if it contains
endpoint
devices that have store and forward and time management features, which are
traditionally
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CA 02831119 2013-10-23
associated with fixed network devices. These devices can be used as described
herein to speed
data collection by the mobile device 508, but can also supply day-to-day time
management,
corrections, and restoration in between periodic (e.g., monthly) visits by the
mobile device
508. Such devices do not need to be part of every endpoint or throughout the
network. Rather,
they can be distributed at critical locations where higher performance is
needed.
101031 In some embodiments, the mobile device 508, such as a hybrid mobile
interrogator, can
improve travel speeds and decrease travel time by taking advantage of the
fixed network type
devices that are deployed in a mobile network. For example, the mobile device
508 may
communicate directly with always-on devices, such as electric meters,
repeaters, and
collectors, using the necessary LAN and/or WAN protocol. The mobile device 508
can also
read either data pertaining either to a particular local device or data
pertaining to
downstream devices that is being relayed, including, for example, sleepy
devices and other
always-on devices. The mobile device 508 may exercise a preference for
communication with
always-on devices, which hold relay data for the sleepy devices. Such a
preference may be
desirable because the always-on devices do not require a time-consuming wake-
up process. In
some embodiments, the mobile device 508 may communicate directly with
collectors and may
gather the data that has been consolidated from downstream devices and
partially processed. The
mobile device 508 may also apply algorithms that consider consolidated data
collected from the
always-on endpoint devices, repeaters, and collectors. In this way, the mobile
device 508 can
reduce the number of standalone endpoint devices that still need to be
traveled to.
101041 Accordingly, rather than having to contact each endpoint, the mobile
device 508 may
only contact the endpoints that are not already present in the consolidated
data. This may reduce
the time required for multiple wake ups and exchanges, and travel to diverse
locations. The
remaining route can be adjusted in real time to target only the "missing"
nodes that need to be
contacted individually.
101051 Figure 6 is a process flow diagram illustrating an example method 600
for consolidated
data collection. At act 602, an upstream device receives data from a
downstream device. The
upstream device may be, for example, an always-on device such as an electric
meter, repeater or
collector. The downstream device may be, for example, a battery powered device
such as a
water or gas meter. The data received from the downstream device may include,
for example,
metering data from the downstream device. At act 604, a mobile device
establishes
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CA 02831119 2013-10-23
. '
communication with the upstream device, and, at act 606, the mobile device
receives
consolidated data. The consolidated data may include local data from the
upstream device along
with the additional data received from the downstream device at act 602. Thus,
for example, the
mobile device is able to receive consolidated data associated with both the
upstream device and
the downstream device without the need to establish direct communication with
the downstream
device.
[0106] Using a mobile interrogator device can realize a number of enhancements
to both fixed
and mobile networks. For example, when gathering data, the mobile interrogator
device can have
a variety of communication paths in the upstream and downstream directions, to
allow real time
data and status reporting associated with both LAN communication and WAN
communication.
With respect to WAN communication, both the established WAN method used by the
meter
network and independent, more reliable back-up communication paths can be
employed.
[0107] During a WAN, LAN, or electrical outage in a fixed or mobile network
the mobile
interrogator device can be sent out on routes to communicate with endpoint
devices of interest,
and, in doing so, collect outage and restoration data in specific areas of
concern. Data can be
gathered to produce outage and restoration reports so repair teams can be
applied quickly and
efficiently.
[0108] In addition to the fixed network and mobile modes described above,
network nodes may
also operate in a hybrid mode in which they may be capable of performing both
fixed network
and mobile communications. It should also be noted that, in some cases, either
or both of the
fixed network and mobile modes may provide this hybrid capability themselves
without the need
to formally switch to a separate "hybrid" mode of operation. Furthermore, the
mobile
interrogator device can command nodes to switch between different network
modes of operation,
e.g., fixed, mobile, and hybrid modes. This may be beneficial, for example,
when the utility
company evolves the desired behavior of a network and the nodes in a network.
[0109] Accordingly, using a hybrid mobile interrogator device may allow
utility companies to
blur the boundaries of fixed and mobile networks and selectively operate their
network in fixed,
mobile, or both modes simultaneously. This may allow advantageous performance
and reliability
compared to networks that have to operate in either a purely fixed mode or a
purely mobile
mode.
CA 02831119 2013-10-23
[0110] As set forth above, mobile interrogators, such as the mobile device 508
of Figure 5, are
traditionally used in Automatic Meter Reading (AMR) utility networks to gather
very basic
information such as monthly consumption. By contrast, fixed Advanced Metering
Infrastructure
(AMI) networks typically offer more information, but do not traditionally
employ mobile
interrogators. According to various embodiments disclosed herein, the
additional information
provided by an AMI system, as well as other additional information, may be
provided to a
mobile interrogator. Furthermore, this additional information may be conveyed
using enhanced
user interface features that may be implemented in a mobile interrogator.
These enhanced user
interface features may enhance an operator's ability to manage and interrogate
endpoints in both
AMR and AMI and other networks. The enhanced user interface features may, for
example,
convey information using various colors, shapes, and sounds. Touch input can
be also be used to
perform various functions as set forth below.
101111 Figure 7 depicts an example user interface 700 that may incorporate a
number of
improvements. The user interface 700 may be presented on a display of the
mobile device 508 of
Figure 5 and may include a visual representation of nodes in a network. The
visual representation
may incorporate different visual indicators, such as different colors, shapes,
or icons, to indicate
different types of nodes, different states of nodes, and/or different read
types associated with
nodes. These visual indicators may be superimposed on a street map, which is
not depicted in
Figure 7. The user interface 700 may also include audio and/or visual warnings
and status
display messages. Further, the user interface 700 may incorporate a touch
sensitive component.
For instance, as shown in Figure 7, the user interface 700 may use one or more
on-screen buttons
to allow the user to generate a variety of different reports or to access
control or configuration
options. In addition, the user interface 700 may allow the user to use touch
to change the shape
and size of a search window or to select devices to include or exclude from a
route.
101121 The user interface 700 may use different colors, shapes, or icons to
indicate different
types of devices. For example, blue shapes or icons 702 (depicted as white in
Figure 7) may be
used to indicate water meters, red shapes or icons 704 (depicted as black in
Figure 7) may be
used to indicate electric meters, and brown or black shapes or icons may be
used to indicate gas
meters. Other colors, shapes, or icons can be used to indicate other types of
devices, such as, for
example, transformer monitors, repeaters, and gateways.
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CA 02831119 2013-10-23
[0113] Different shapes, sizes, icons, or colors can be used to indicate
different states. For
instance, one shape, e.g., a triangle, may be used to indicate that a meter is
unread, while another
shape, e.g., a square, may indicate that the meter has been read. Still
another shape, e.g., a circle,
may indicate that a read attempt has failed. Yet another shape may indicate
whether a meter is
connected or disconnected. Still other indicators may be used to indicate
status flags, error flags,
process errors (e.g., disconnect failed, demand reset failed, etc.), load side
voltage, low battery,
tampering, etc.
[0114] In some embodiments, the user interface 700 may indicate different read
types
associated with an endpoint device, including, for example, a history read, a
standard read, a
request for a demand reset, a connect or disconnect request, or other special
read types. These
and other read types may be represented using different colors, shapes, or
icons. The user
interface 700 may also indicate a "verify read" error, in which the visual
read by the operator is
inconsistent with the RF read by the mobile interrogator device. Further, the
user interface 700
may indicate meters that appear to be stolen or improperly located or out of
place.
[0115] In addition to using different shapes, icons, and/or colors, the user
interface 700 may
incorporate audio and/or visual warnings and status display messages to, for
example, assist the
user in adjusting the speed and/or direction of the vehicle for proper meter
operation. For
instance, a warning may be used to advise the user to pull the vehicle over to
perform a connect
or disconnect operation. A status display message may be used to advise the
user that it is
acceptable to drive faster because (1) the read rate exceeds preset threshold
and the user is not
speeding, or (2) there are no meters in the window and the user is not
speeding. On the other
hand, a warning may be used to prompt the user to drive more slowly, either
because the read
rate is lower than preset acceptable threshold or because the user is
exceeding a speed limit that
is set by an operator or by law. A warning or status message may be used to
warn the user to be
prepared to slow down because the user is entering an area of high density or
because the user is
approaching meters that may require more time to read or that may require the
vehicle to be
pulled over, such as an electric connect/disconnect, demand reset, etc. In
some embodiments, a
warning or status message may be used to prompt the user to turn around
because the user
missed a read on a meter or because the user is prematurely leaving a
geographic area that is
associated with the route. Audio warnings may indicate process errors, such as
a missing meter
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CA 02831119 2013-10-23
=
or errors encountered during attempts to perform a connect or disconnect
operation or
communicate with a meter.
[0116] In some embodiments, the user interface 700 may incorporate a touch
sensitive
component. For instance, as shown in Figure 7, the user interface 700 may use
one or more on-
screen buttons to allow the user to generate a variety of different reports or
to access control or
configuration options. As a non-limiting example, an on-screen button 706 may
cause the display
to show the user's progress along the route. Another on-screen button 708 may
allow the user to
zoom in or out of the map or relocate the map. Yet another on-screen button
710 may allow the
user to generate any of a variety of reports. Still another on-screen button
712 may allow the user
to access global positioning system (GPS) functions.
[0117] In some embodiments, a mobile interrogation system may be capable of
interrogating
and managing both AMR and AMI utility networks and other networks. Certain
other features
may improve mobile interrogation of both AMR and AMI utility networks and
other networks.
For example, mobile interrogation may be improved by optimized route
navigation. Typically,
mobile endpoint interrogation in AMR or AMI utility networks is performed by
route assignment
to a mobile system. The route is generated using route management software,
and endpoints are
included based on a set of utility criteria. The route typically includes the
address and geospatial
data collected during endpoint installation. Once the route is generated,
traditionally the operator
must determine how to optimally traverse the route.
[0118] Mobile interrogation may be improved by a route navigation feature that
determines a
more efficient or optimum interrogation route to traverse for the operator.
The user may input
meter route preference criteria (for example, fastest time, fewest miles,
avoid congested areas,
and/or avoid tolls) and endpoint meter attribute filters (for example, outage
meters, service
connect, service disconnect, demand reset, and/or verify read). An optimized
route generation
algorithm may be applied to, for example, the user preferences, meter route
preference criteria,
meter endpoint attribute filters, historical endpoint results and GPS data.
The result may be a
turn-by-turn or other detailed driving plan that directs the mobile
interrogator through the route
to gather data from the specific target endpoints. If desired, this more
efficient route may change
for each new data collection operation.
[0119] The route navigation feature may be based on additional data, such as,
for example,
data that is specific to each endpoint device. This data may be uniquely
identified and may
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CA 02831119 2013-10-23
supply information about attributes such as, for example, radio performance
and geographical
location related to this optimization. In particular, Figure 8 is a diagram
illustrating an example
user interface 800 for collecting data from endpoint devices identified by
their serial number and
encoded status information. The user interface 800 may include a number of
columns 802
indicating, for example, an address, a serial number, encoded status
information, and a reading
associated with individual entries, which are represented in rows 804 of the
user interface. Figure
9 is a diagram illustrating an example user interface 900 for displaying
geographic and other data
associated with a particular endpoint device. The user interface 900 may
display, for example,
account information associated with the endpoint device, as well as historical
data. Figure 10 is a
diagram illustrating an example user interface 1000 for displaying packet
performance and other
data associated with a particular endpoint device. This information may be
displayed, for
example, as a table that shows the total number of packets transmitted,
received good, and
received bad, e.g., with a failed CRC check. For packets received, the totals
may include all
packets regardless of the utility identifier.
[0120] As another example, mobile interrogation may be improved by an adaptive
transmitter
control feature that may extend the battery life of battery operated endpoint
devices. Historically,
battery operated gas and water modules that require a wakeup signal are
subjected to the wakeup
signal continuously during route interrogation even when no modules are
currently under
interrogation. The result of the current practice is shortened battery life of
the battery-powered
gas and water modules and increased power demand on the data collection
vehicle.
10121] The adaptive transmitter control feature may extend module battery life
by, for
example, turning off the wakeup transmitter when the mobile interrogator
determines that it is
stopped and/or that no endpoints needing interrogation are included within the
interrogation
window. In some cases, other factors may also be considered such as the
duration for which
mobile interrogator is stopped and also the proximity of endpoints needing
interrogation outside
the interrogation window. For example, if the mobile interrogator is only
stopped briefly (e.g.,
stop sign or red light), then the transmitter may remain on. Also, if there
are endpoints needing
interrogation just outside the window, then, in some cases, the transmitter
may also remain on.
These determinations may be made based on, for example, GPS data. The mobile
interrogator
may use, for example, an extended interrogation window area, the speed and
direction the mobile
interrogator is traveling, and the time required to turn on the transmitter to
ensure the endpoint
34
CA 02831119 2013-10-23
. ,
'
devices under interrogation will be awake as they enter the window, while
minimizing endpoint
wakeup signal exposure.
[0122] In some embodiments, the mobile interrogation may be enhanced by
controlling
additional meter functions. These may, for example, include some functions
that may have
typically been previously performed only on fixed AMI networks. Historically,
mobile
interrogation of endpoint devices in AMR and AMI networks consists of
gathering very basic
consumption information. The mobile device 508 according to the disclosed
embodiments may
control a number of advanced gas, water, and electric meter functions, such as
demand resets and
gas, water, and electric service disconnect and connect operations for
internal and external
switches. The mobile device 508 may also perform meter configuration of non-
networked
endpoint devices. The mobile device 508 may change the operating mode of
various devices
between drive-by, hybrid, and fixed network modes. For electric meters, the
mobile device 508
may collect data pertaining to delivered power and supplied power, perform
transformer
monitoring, and/or generate or use load profiles. Various readings, including
voltage, current,
VAR, VA, and real power readings, may be performed. The mobile device 508 may
also perform
net metering. In addition, the mobile device 508 may control time of use or
time of use
schedules. Various synchronization operations may be performed. For example,
the mobile
device 508 may provide clock synchronization between a mobile network and a
fixed network,
or between an endpoint device's clock and a mobile network's clock. Outage
calculations may
be performed based on an endpoint device's internal clock.
[0123] In some embodiments, the mobile device 508 may incorporate a meter
performance
trending function that uses historical endpoint interrogation data to report
potential problems
with endpoint devices to the operator. This may be accomplished, for example,
by recording the
reception range, response rate and other readings between the mobile device
508 and each
endpoint device. Algorithms may then be applied to discover issues, such as
gas and water
endpoints approaching battery end-of-life and electric meter malfunction.
[0124] The mobile device 508 may incorporate an adaptive display
resynchronization feature
that allows the operator to hot swap a failed video display device with a
functioning video
display device without restarting the mobile device 508.
[0125] In some embodiments, the mobile device 508 may have the capability to
determine
whether a meter has been stolen and, if so, to attempt to locate it within the
utility's network. For
CA 02831119 2013-10-23
example, the mobile device 508 may use historical Received Signal Strength
Indicator (RSSI)
and read location data to infer unauthorized meter movement relative to
current interrogation
data. Further, historical read history data may indicate that a user-supplied
threshold of "no
reading" has occurred.
[0126] Once it is determined that a meter has been stolen, the mobile device
508 may attempt
to determine the location of the meter. The missing meter may be included in
the utility
company's routes without geospatial location data. When the mobile device 508
receives a
response from the stolen meter, the user can gather RSSI data for non-real
time data processing
using a matrix of the RSSI data to predict where the meter is located.
Alternatively, the mobile
device 508 can guide the user progressively closer to the missing meter
location by attempting to
maximize the RSSI value in the response.
[0127] In some embodiments, mobile interrogation may be enhanced by encrypting
communications and managing endpoint encryption. For example, the mobile
device 508 may
enable or disable encrypted endpoint communication. Endpoint encryption keys
may be updated.
Stranded fixed network endpoint devices may be rekeyed. Mobile network key
management
methods may be synchronized with overlapping fixed networks to achieve a
standard level of
security across the network. The mobile device 508 may provide key management
for a mobile-
only network. In addition, the mobile device 508 may enable utility rekeying
in mobile, fixed
and blended (AMR/AMI) networks.
[0128] In some embodiments, mobile interrogation data may be used to create
outage and
restoration maps and present them graphically in real-time or at other time
intervals. The map's
background colors may highlight areas of outage and restoration to easily
guide restoration crews
during an outage.
101291 All or portions of the subject matter disclosed herein may be embodied
in hardware,
software, or a combination of both. When embodied in software, the methods and
apparatus of
the subject matter disclosed herein, or certain aspects or portions thereof,
may be embodied in
the form of program code (e.g., computer executable instructions). This
program code may be
stored on a computer-readable medium, such as a magnetic, electrical, or
optical storage
medium, including without limitation, a floppy diskette, CD-ROM, CD-RW, DVD-
ROM, DVD-
RAM, magnetic tape, flash memory, hard disk drive, or any other machine-
readable storage
medium, wherein, when the program code is loaded into and executed by a
machine, such as a
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CA 02831119 2013-10-23
computer or server, the machine becomes an apparatus for practicing the
invention. A device on
which the program code executes will generally include a processor, a storage
medium readable
by the processor (including volatile and non-volatile memory and/or storage
elements), at least
one input device, and at least one output device. The program code may be
implemented in a
high level procedural or object oriented programming language. Alternatively,
the program code
can be implemented in an assembly or machine language. In any case, the
language may be a
compiled or interpreted language. When implemented on a general-purpose
processor, the
program code may combine with the processor to provide a unique apparatus that
operates
analogously to specific logic circuits.
101301 While systems and methods have been described and illustrated with
reference to
specific embodiments, those skilled in the art will recognize that
modification and variations may
be made without departing from the principles described above and set forth in
the following
claims. Accordingly, reference should be made to the following claims as
describing the scope of
the present invention.
37
