U.S. patent application number 11/341646 was filed with the patent office on 2008-01-17 for power line communications module and method.
Invention is credited to Terry L. Bernstein, Kevin F. Corcoran, James Douglas Mollenkopf.
Application Number | 20080012724 11/341646 |
Document ID | / |
Family ID | 38328094 |
Filed Date | 2008-01-17 |
United States Patent
Application |
20080012724 |
Kind Code |
A1 |
Corcoran; Kevin F. ; et
al. |
January 17, 2008 |
Power line communications module and method
Abstract
A device and method for communicating user data and utility
metrology data over a power line is provided. In one embodiment,
the method includes measuring a utility parameter to provide the
utility data; storing the utility data in memory; transmitting the
utility data over the power line; receiving first data via the
power line from a first device; and transmitting the first data
over the power line to a second device. In addition, the method may
include receiving the first data and transmitting the first data
with different encryption keys and also determining if the first
data includes control data.
Inventors: |
Corcoran; Kevin F.;
(Middletown, MD) ; Mollenkopf; James Douglas;
(Fairfax, VA) ; Bernstein; Terry L.; (Middletown,
MD) |
Correspondence
Address: |
CAPITAL LEGAL GROUP, LLC
1100 River Bay Road
Annapolis
MD
21409
US
|
Family ID: |
38328094 |
Appl. No.: |
11/341646 |
Filed: |
January 30, 2006 |
Current U.S.
Class: |
340/870.02 |
Current CPC
Class: |
Y04S 20/30 20130101;
Y02B 90/20 20130101; G01D 4/004 20130101 |
Class at
Publication: |
340/870.02 |
International
Class: |
G08C 15/06 20060101
G08C015/06 |
Claims
1. A method of communicating data over a power line, comprising:
measuring a utility parameter to provide utility data; storing the
utility data in memory; transmitting the utility data over the
power line; receiving first data via the power line from a first
device; and transmitting the first data over the power line to a
second device.
2. The method of claim 1, further comprising: receiving second data
via the power line; and not transmitting the second data over the
power line.
3. The method of claim 1, wherein the first device comprises a
medium voltage (MV) access device.
4. The method of claim 1, wherein the first device comprises a user
device.
5. The method of claim 1, further comprising decrypting the
received first data with a first key; and encrypting the first data
with a second key prior to said transmitting of the first data.
6. The method of claim 1, wherein the first data is received in a
first frequency band and transmitted in a second frequency band
different from the first frequency band.
7. The method of claim 1, further comprising: determining whether
the first data is to be repeated; and transmitting the first data
over the power line only if the first user data is to be
repeated.
8. The method of claim 7, further comprising determining whether
the first data includes a command if the first data is not to be
repeated.
9. The method of claim 1, wherein said receiving first data and
said transmitting first data are performed with different
encryption keys.
10. The method of claim 1, wherein further comprising determining
if the first data includes control data.
11. The method of claim 1, wherein said receiving and said
transmitting of the first data are performed by the same modem.
12. The method of claim 1, wherein said receiving and said
transmitting of the first data are performed by different
modems.
13. The method of claim 1, further comprising receiving a command
to disable repeating.
14. The method of claim 1, further comprising receiving a command
that includes a request to transmit the utility data.
15. The method of claim 1, further comprising: receiving second
data via the power line from the second device; and transmitting
the second data over the power line to the first device.
16. A device for communicating user data and utility over a power
line; comprising: a memory configured to store utility data; a
processor in communication with said memory; a communication module
in communication with said processor and configured to be
communicatively coupled to the power line; wherein said processor
is configured to cause said module to transmit utility data over
the power line; and wherein said processor is configured to cause
said module to receive and transmit user data via the power
line.
17. The device of claim 16, wherein the power line includes a first
and second energized conductor and said module is configured to be
communicatively coupled to the first and the second energized
conductor to differentially transmit data signals over the
energized conductors.
18. The device of claim 16, wherein the power line comprises an
external power line supplying power to a customer premises and the
user data includes data received from a user device in the customer
premises.
19. The device of claim 16, wherein the user data includes data
received from a MV power line access device.
20. The device of claim 19, wherein the MV power line access device
comprises a transformer bypass device.
21. The device of claim 16, wherein said module is configured to
receive and decrypt user data with a first encryption key and to
encrypt and transmit user data with a second encryption key.
22. The device of claim 21, wherein said module is further
configured to receive and decrypt user data with the second first
encryption key and to encrypt and transmit user data with the first
encryption key.
23. The device of claim 16, wherein said communication module
includes a first and second modem configured to be coupled to the
power line.
24. The device of claim 23, further comprising a data signal
impedance configured to be coupled to the power line to between
said first and second modems.
25. The device of claim 23, wherein said first and second modem are
configured to communicate using different encryption keys.
26. The device of claim 16, wherein said communication module
includes only a single modem.
27. A method of communicating utility data and non-utility data
over a power line, comprising: storing the utility data in memory;
transmitting the utility data over the power line; receiving first
data via the power line; determining whether the first data is to
be repeated; and transmitting the first data over the power line if
the first data is to be repeated.
28. The method of claim 27, further comprising determining whether
the first data includes a command.
29. The method of claim 27, wherein said receiving the first data
and said transmitting the first data are performed with different
encryption keys.
30. The method of claim 27, wherein said determining includes
determining if the first data includes control data.
31. The method of claim 27, wherein said receiving the first data
and said transmitting the first data are performed in different
frequency bands.
32. The method of claim 27, wherein said receiving the first data
and said transmitting the first data are performed by the same
modem.
33. The method of claim 27, further comprising receiving a command
to disable repeating.
34. The method of claim 27, further comprising receiving a command
that includes a request to transmit the utility data.
35. The method of claim 27, further comprising receiving a command
to enable repeating.
36. The method of claim 27, wherein said transmitting the utility
data is performed periodically.
37. The method of claim 27, wherein said transmitting the utility
data is performed intermittently.
38. The method of claim 27, further comprising: receiving program
code via the power line; and storing the program code in
memory.
39. The method of claim 27, further comprising receiving second
data via the power line; and transmitting the second data over the
power line.
40. The method of claim 39, wherein said receiving the first data
and said transmitting the second data are performed with a first
encryption key; and said receiving the second data and said
transmitting the first data are performed with a second encryption
key .
41. The method of claim 27, further comprising transmitting an
alert over the power line based on the value of the utility data.
Description
FIELD OF THE INVENTION
[0001] The present invention generally relates to data
communications over a power distribution system and more
particularly, to a communications module for communicating utility
meter data and power line communications data.
BACKGROUND OF THE INVENTION
[0002] Well-established power distribution systems exist throughout
most of the United States, and other countries, which provide power
to customers via power lines. With some modification, the
infrastructure of the existing power distribution systems can be
used to provide data communication in addition to power delivery,
thereby forming a power line communication system (PLCS). In other
words, existing power lines that already have been run to many
homes and offices, can be used to carry data signals to and from
the homes and offices. These data signals are communicated on and
off the power lines at various points in the power line
communication system, such as, for example, near homes, offices,
Internet service providers, and the like.
[0003] There are many challenges to overcome in order to use power
lines for data communication. Power lines are not designed to
provide high speed data communications and can be very susceptible
to interference. Additionally, federal regulations limit the amount
of radiated energy of a power line communication system, which
therefore limits the strength of the data signal that can be
injected onto power lines (especially overhead power lines).
Consequently, due to the attenuation of power lines, communications
signals typically will travel only a relatively short distance on
power lines. In addition, the distance may vary from location to
location.
[0004] Power line communication systems often communicate with user
devices in the customer premises, which typically are coupled
directly or indirectly to an internal low voltage (LV) power line
network. This communication typically involves transmitting signals
along the external LV power lines, through an electric meter, and
along the internal LV power lines to the user device. However, the
electric meter, which measures the power consumed by the customer
premises and is connected to the LV power lines, sometimes
attenuates the data signals. Additionally, in some instances the
length of the LV power lines and associated attenuation can hamper
or prevent reliable communications. Additionally, ingress noise and
noise from home appliances can degrade communications
performance.
[0005] Automated meter reading (AMR) has been investigated as a
means for reducing the cost of reading meters. The high capital
cost of replacing meters and building an AMR system in a large
geographical area has hindered wide scale adoption of automated
meter reading.
[0006] Thus, there is a need for a communications module and method
that facilitates automated electric meter reading and reliable
communication of user data signals that can be dynamically
configured and reconfigured by a network management system. These
and other advantages may be provided by various embodiments of the
present invention.
SUMMARY OF THE INVENTION
[0007] The present invention includes a device and method for
communicating user data and utility metrology data over a power
line. In one embodiment, the method includes measuring a utility
parameter to provide the utility data; storing the utility data in
memory; transmitting the utility data over the power line;
receiving first data via the power line from a first device; and
transmitting the first data over the power line to a second device.
In addition, the method may include receiving the first data and
transmitting the first data with different encryption keys and also
determining if the first data includes control data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The invention is further described in the detailed
description that follows, by reference to the noted drawings by way
of non-limiting illustrative embodiments of the invention, in which
like reference numerals represent similar parts throughout the
drawings. As should be understood, however, the invention is not
limited to the precise arrangements and instrumentalities shown. In
the drawings:
[0009] FIG. 1 is a diagram of an exemplary power distribution
system with which the present invention may be employed;
[0010] FIG. 2 is a diagram of a portion of an example power line
communications system;
[0011] FIG. 3 is a diagram of an example embodiment of a
communication module according to the present invention;
[0012] FIG. 4 is a block diagram of an example embodiment of a
communication module, in accordance with the present invention;
and
[0013] FIG. 5 is a block diagram of an example embodiment of a
communication module, in accordance with the present invention.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0014] In the following description, for purposes of explanation
and not limitation, specific details are set forth, such as
particular networks, communication systems, computers, terminals,
devices, components, techniques, PLCS, data and network protocols,
software products and systems, operating systems, development
interfaces, hardware, etc. in order to provide a thorough
understanding of the present invention.
[0015] However, it will be apparent to one skilled in the art that
the present invention may be practiced in other embodiments that
depart from these specific details. Detailed descriptions of
well-known networks, communication systems, computers, PLCS,
terminals, devices, components, techniques, data and network
protocols, software products and systems, operating systems,
development interfaces, and hardware are omitted so as not to
obscure the description of the present invention.
[0016] As shown in FIG. 1, power distribution systems typically
include components for power generation, power transmission, and
power delivery. A transmission substation typically is used to
increase the voltage from the power generation source to high
voltage (HV) levels for long distance transmission on HV
transmission lines to a substation. Typical voltages found on HV
transmission lines range from 69 kilovolts (kV) to in excess of 800
kV.
[0017] In addition to HV transmission lines, power distribution
systems include MV power lines and LV power lines. MV typically
ranges from about 1000 V to about 100 kV and LV typically ranges
from about 100 V to about 800 V. Transformers are used to convert
between the respective voltage portions, e.g., between the HV
section and the MV section and between the MV section and the LV
section. Transformers have a primary side for connection to a first
voltage (e.g., the MV section) and a secondary side for outputting
another (usually lower) voltage (e.g., the LV section).
Transformers used between the MV section and the LV section are
often referred to as distribution transformers or as step down
transformers, because they "step down" the voltage to some lower
voltage. Transformers, therefore, provide voltage conversion for
the power distribution system. Thus, power is carried from
substation transformer to a distribution transformer over one or
more MV power lines. Power is carried from the distribution
transformer to the customer premises via one or more LV power
lines.
[0018] In addition, a distribution transformer may function to
distribute one, two, or three, phase voltages to the customer
premises, depending upon the demands of the user. In the United
States, for example, these local distribution transformers
typically feed anywhere from one to ten homes, depending upon the
concentration of the customer premises in a particular area.
Distribution transformers may be pole-top transformers located on a
utility pole, pad-mounted Underground Residential Distribution
(URD) transformers located on the ground, or transformers located
under ground level.
[0019] One example of a portion of a conventional PLCS is shown in
FIG. 2. In this example, two bypass devices (BD) 100a and 100b are
used to communicate data signals around the distribution
transformers that would otherwise filter such data signals,
preventing them from passing through the transformer or
significantly degrading them. Thus, the BD 100 is the gateway
between the LV power line subnet (i.e., the LV power line connected
to the distribution transformer and the devices that are coupled to
the LV power lines) and the MV power line and communicates signals
to and from user devices at the customer premises (CP) of the low
voltage subnet 61.
[0020] In this example embodiment, the BD 100 provides
communication services for the user, which may include security
management, routing of Internet Protocol (IP) packets, filtering
data, access control, service level monitoring, signal processing
and modulation/demodulation of signals transmitted over the power
lines.
[0021] This example portion of a PLCS also includes a backhaul
point 10. The backhaul point 10 is an interface and gateway between
a portion of a PLCS (e.g., an MV run) and a traditional non-power
line telecommunications network. One or more backhaul points (BP)
10 may be communicatively coupled to an aggregation point (AP) 20
that in many embodiments may be at (e.g., co-located with), or
connected to, the point of presence to the Internet. The BP 10 may
be connected to the AP 20 using any available mechanism, including
fiber optic conductors, T-carrier, Synchronous Optical Network
(SONET), or wireless techniques well known to those skilled in the
art. Thus, the BP 10 may include a transceiver suited for
communicating through the communication medium that comprises the
backhaul link.
[0022] The PLCS also may include a power line server (PLS) that is
a computer system with memory for storing a database of information
about the PLCS and includes a network element manager (NEM) that
monitors and controls the PLCS. The PLS allows network operations
personnel to provision users and network equipment, manage customer
data, and monitor system status, performance and usage. The PLS may
reside at a remote network operations center (NOC), and/or at a
PLCS Point of Presence (POP), to oversee a group of communication
devices via the Internet. The PLS may provide an Internet identity
to the network devices by assigning the devices (e.g., user
devices, BDs 100, (e.g., the LV modems and MV modems of BDs), BPs
10, and AP 20) IP addresses and storing the IP addresses and other
device identifying information (e.g., the device's location,
address, serial number, etc.) in its memory. In addition, the PLS
may approve or deny user devices authorization requests, command
status reports, statistics and measurements from the BDs, and BPs,
and provide application software upgrades to the communication
devices (e.g., BDs, BPs, and other devices). The PLS, by collecting
electric power ,distribution information and interfacing with
utilities' back-end computer systems may provide enhanced power
distribution services such as automated meter reading, outage
detection, restoration detection, load balancing, distribution
automation, Volt/Volt-Amp Reactance (Volt/VAr) management, and
other similar functions. The PLS also may be connected to one or
more APs and/or core routers directly or through the Internet and
therefore can communicate with any of the BDs, user devices, and
BPs through the respective AP and/or core router.
[0023] The PLCS may further include indoor low voltage repeaters
and outdoor low voltage repeaters. Indoor low voltage repeaters may
be plugged into a wall socket inside the customer premises. Outdoor
low voltage repeaters may be coupled to the external low voltage
power line conductors extending from the transformer and therefore,
be located between the customer premises and the BD 100. Both the
indoor low voltage repeaters and outdoor low voltage repeaters
repeat data on the low voltage power line to extend the
communication range of the BD 100 and power line modem.
[0024] At the user end of the PLCS of this example system, data
flow originates from a user device, which provides the data to a
power line modem (PLM) 50, which is well-known in the art.
[0025] The user device connected to the PLM 50 may be any device
capable of supplying data for transmission (or for receiving such
data) including, but not limited to a computer, a telephone, a
telephone answering machine, a fax, a digital cable box (e.g., for
processing digital audio and video, which may then be supplied to a
conventional television and for transmitting requests for video
programming), a video game, a stereo, a videophone, a television
(which may be a digital television), a video recording device
(which may be a digital video recorder), a home network device, a
direct load control switch, utility distribution automation
equipment, or other device. The PLM 50 transmits the data received
from the user device through the LV power lines to a BD 100 and
provides data received from the LV power line to the user device.
The PLM 50 may also be integrated with the user device, which may
be a computer. In addition and as discussed herein, the functions
of the PLM may be integrated into a smart utility meter such as a
gas meter, electric meter, water meter, or other utility meter to
thereby provide automated meter reading (AMR).
[0026] The BD 100 typically receives data from the user devices
coupled to its LV power line subnet and then transmits the data to
(and receives the data from) the backhaul point 10, which, in turn,
transmits the data to (and receives the data from) the AP 20. The
AP 20 then transmits the data to (and receives the data from) the
appropriate destination (perhaps via a core router), which may be a
network destination (such as an Internet address) in which case the
packets are transmitted to, and pass through, numerous routers
(herein routers are meant to include both network routers and
switches) in order to arrive at the desired destination. A detailed
description of an example PLCS, its components and features is
provided in U.S. patent application Ser. No. 11/091,677 filed Mar.
28, 2005, Attorney Docket No. CRNT-0239, entitled "Power Line
Repeater System and Method," which is hereby incorporated by
reference in its entirety. A detailed description of another
example PLCS, its components and features is provided in U.S.
patent application Ser. No. 10/973,493 filed Oct. 26, 2004,
Attorney Docket No. CRNT-0229, entitled "Power Line Communications
System and Method of Operating the Same," which is hereby
incorporated by reference in its entirety. The present invention
may be used with networks as described in the above patent
applications or others. Thus, the invention is not limited to a
particular PLCS, PLCS architecture, or topology.
[0027] Referring to FIG. 2, one example PLCS includes a BD 100 at
each distribution transformers 60a and 60b to service the user
devices coupled to the respective LV power line subnet. Thus, BD
100a is coupled to backhaul point 10 via the MV power line and also
coupled to LV power line subnet 61a to provide communications to
the user devices coupled thereto. In this example, LV power line
subnet 61a includes the LV power lines connected to distribution
transformer 60a, which may be connected to between one and ten (and
sometimes more) customer premises (CP). One or more of the customer
premises may include one or more power line modems 50 and
associated user devices that are connected to the internal power
lines such as, for example, at CP 119a and 119b.
[0028] Similarly, BD 100b is coupled to backhaul point 10 via the
MV power line and also coupled to LV power line subnet 61b to
provide communications to the user devices coupled thereto. In this
example, LV power line subnet 61b includes the LV power lines
coupled to distribution transformer 60b. One or more of the
customer premises receiving power via LV power line subnet 61b may
include one or more PLMs 50 and the associated user devices
connected thereto such as, for example, at CP 119c, 119d, and 119e.
Thus, as shown in FIG. 2, the bypass device 100 typically
communicates via the external low voltage power lines 62, the power
meter 300, and internal power lines to the user device. In some
instances however, the electric meter and the length of the low
voltage power lines (both internal and external) may attenuate the
data signals to the point where communications are prevented or
degraded and/or are no longer reliable.
[0029] FIG. 3 depicts an example communications module 2000 that
provides repeating of some power line communication data (user
data) and facilitates automated reading of the power meter 300. In
other implementations, the module 2000 may facilitate automated
reading of additional or other meters such as gas meters and/or
water meters. This example embodiment may be integrated into or
form part of the power meter. In one example embodiment, the module
2000 may be implemented on a circuit card that is inserted into an
electronic meter. In other embodiments, all or part of the module
2000 may be disposed in the meter collar.
[0030] This example embodiment includes a power line interface 2020
which is coupled to modem 2022. Power line interface 2020 may
include impedance matching circuitry, a band filter, an amplifier,
power signal isolation circuitry, transmit and receive circuitry,
and other conditioning circuitry. As shown, power line interface
2020 may be coupled to both energized conductors L1 and L2 and may
transmit data by differentially coupling the data signals onto the
power line conductors (e.g., via a transformer therein) and
similarly receiving the data. In addition, the power line interface
2020 may provide frequency translation. While this embodiment
communicates over two energized power line conductors, other
embodiments may communicate over one energized conductor or three
energized conductors (three phase service).
[0031] The modem 2022 may be a HomePlug compliant or compatible
power line modem (e.g., substantially comply or compatible with
HomePlug 1.0, Turbo, or AV) and employ OFDM for communications over
the power line. The modem 2022 is communicatively coupled to the
processor 2040. The processor 2040 may be in communication with
memory 2045, which may include volatile and non-volatile random
access memory (RAM) which may be used to store utility metrology
data, including power usage data, collected from the meter 300 and
program code to be executed by the processor 2040. Other utility
metrology data (or referred to herein as utility data) may include,
but is not limited to Voltage (peak/average/threshold) data,
Current (peak/average/threshold) data, power factor data, phase
angle data, peak power data, average power data, voltage sag data,
voltage swell data, neutral current, peak reverse power data, and
average reverse power data. As will be evident to one skilled in
the art, some of these data types may comprise raw measurements and
others may be derived from raw measurement data. Additionally, one
or more of these may cause the processor 2040 to generate (and
transmit) an alert such as an Alert on detection of reverse power,
voltage sag, voltage swell, voltage out of limit (too high or low),
etc.
[0032] New program code may also be received via the energized
conductors (e.g., the external power line conductors) from a
network element, such as a bypass device, of the PLCS. The new code
may then be stored in flash memory for execution by the processor
2040. The module 2000 may be configured by to enable or disable
repeating of power line communications via a command from a network
element, such as a bypass device, of the PLCS. The enabling or
repeating of PLC data may thus be achieved by the processor 2040
executing program code and in response to receiving a command.
[0033] The processor 2040 may also be in communication with the
meter via a power meter interface 2042 in order to receive data and
perform other AMR processes. A power supply 2055 is coupled to the
processor 2040, modem 2022, and other components to provide power
thereto.
[0034] The utility data (e.g., power usage data) may be received by
the module 2000 and transmitted via the LV power line to a power
line communications system network element, which may be, for
example, a transformer bypass device 100. The network element may
then transmit the utility data (e.g., via the MV power line) to an
upstream device (e.g., a backhaul device 10), which further
transmits the utility data upstream for eventual reception by
utility provider. Additionally, the module 2000 may receive user
data from the bypass device 100 and transmit the data over the LV
power line for reception by one or more user devices in the
customer premises. Similarly, the module 2000 may receive user data
from one or more user devices in the customer premises and transmit
the user data over the LV power line to the bypass device 100 or
other network element. Examples of such a power line communications
systems and network elements are described in the applications
incorporated above.
[0035] In operation, data signals will be received from the
internal LV power line via line interface 2020. After conditioning
by line interface 2020, the signals will be provided to modem 2022.
However, if a data packet received by modem 2022 does not have a
destination address (e.g., media access control address or IP
address) that corresponds to modem 2022, the data packet may be
ignored. In other instances, the data signals received by the modem
2022 may have been encrypted by the transmitting device. If the
modem has the correct encryption key, the modem may successfully
decrypt the data packets. However, if the modem 2022 does not have
the correct encryption key, the modem 2022 will not be able to
successfully decrypt the data packet and the data will be ignored.
A first key may be used for communications between the module 2000
and user devices and a second key may be used for communications
between the module 2000 and its network element (e.g., bypass
device). The processor 2040 may control which keys modem 2022 uses.
If the packet is not correctly addressed or encrypted, the data may
be discarded and not repeated by module 2000. Other means of
selectively repeating the data may also be employed.
[0036] There are various reasons for employing selective repeating
and/or multiple encryption keys. As discussed above, if
communications between the bypass device and the user device are
not reliable, the user device may sometimes receive data from the
bypass device. If the module 2000 is repeating all data packets, it
is possible that the user device (or the bypass device) may receive
the same packet twice (transmitted once from the module and once
from the bypass device), which would likely cause an error. To
prevent this occurrence, the bypass device and the user devices
(i.e., their power line modems) may use different encryption keys
for communications on the LV power line. This creates a logical
isolation of the internal and external networks. Additionally, the
bypass device may communicate with a plurality of user devices in
different customer premises, which are electrically connected by
the LV power lines. Using a different encryption key for each
customer premises ensures that user devices in one customer
premises cannot receive data transmitted by or to user devices in
another customer premises. Additionally, it may be desirable to
repeat user data to increase the signal strength of the user data,
which may allow for increased data speed.
[0037] In an alternate example embodiment, LV power line
communications with the bypass device and the user devices (i.e.,
their power line modems) may use different frequency bands. In this
embodiment, the power line interface 2020 may include frequency
translation circuitry for translation from the 4-21 MHz band to the
20-50 MHz band. Thus, in this embodiment, Homeplug compliant data
signals (e.g., Homeplug 1.0, HomePlug Turbo, or Homeplug AV)
between the module 2000 and user devices may use the 20-50 MHz band
and communications between the module 2000 and the bypass device
may use the 4-21 MHz (or vice versa). Thus, because they
communicate in different frequency bands, the user devices and the
bypass device cannot "accidentally" communicate with each other. In
this embodiment, the power line interface may have two different
input and output filters (one for each band) and two frequency
translation circuits--one for upbanding the output of the modem to
the higher frequency band and one for downbanding the input of the
higher frequency to the modem's native frequency band. This
embodiment may be implemented by having the processor 2040 control
the frequency band at which the power line interface 2020
communicates. Alternately, if a modem that supported two frequency
bands were used, processor 2040 may control the frequency used by
modem 2022. The modem 2022 could also communicate via its native
frequency or frequencies.
[0038] In the first embodiment, if repeating is enabled, and the
data packet is successfully decrypted, the demodulated data packet
is supplied to the processor 2040. Processor 2040 may process the
data packet(s) and if the packet contains a command may perform one
or more activities. Such commands and associated activities may
include transmit utility data, update schedule of transmissions of
utility data, disable repeating, enable repeating, receive and
store new program code, store new IP address, and others. Processor
2040 may determine a data packet includes a command by any suitable
method such as identify packets having a destination IP address
corresponding to that of module 2000, which is stored in memory
2045. If the packet is not a command, the processor 2040 may supply
the same received data packet back to the modem for transmission
onto the LV conductors. In addition to supplying the data packet to
the modem 2022, the processor 2040 also may supply information of
the encryption key to be used to encrypt the data packet (or, in an
alternate embodiment, information to control the frequency band of
transmission). If repeating is disabled, the processor 2040 does
not supply the packet back to the modem 2022 or alternately may
disable the modem 2022. In an alternate embodiment, the data
received by the processor 2040 from modem 2022 also may be
re-addressed by processor 2040 with the destination address (e.g.,
MAC address) of the user device that corresponds to the destination
address of the data packet. Thus, the processor 2040 may include
router (or switch) functionality.
[0039] FIG. 4 illustrates another example implementation of module
2000. This example embodiment, includes a first power line
interface 2010 and a second power line interface 2020, which are in
communication with a first modem 2012, and second modem 2022,
respectively. Line interfaces 2010 and 2020 each may include a
impedance matching circuitry, a band filter, an amplifier, power
signal isolation circuitry, transmit and receive circuitry, and
other conditioning circuitry. As shown, each line interface 2010
and 2020 may be coupled to both energized conductors and may
transmit data by differentially coupling the data signals onto the
power line (e.g., via a transformer therein). The modems 2012 and
2022 may be HomePlug compatible power line modems and employ OFDM
for communications over the power line. Each modem is coupled to an
Ethernet switch/router 2030, which is coupled to a processor 2040.
The processor 2040 may be in communication with memory 2045, which
may include volatile and non-volatile memory and used as discussed
above. Further, the line condition 2050, power supply 2055, power
meter interface 2042, and processor 2040 work substantially the
same as described for the embodiment of FIG. 3. In an alternate
embodiment, processor 2040 may be connected to modems 2012 and 2022
and performs the switch/router functions alleviating the need for a
separate switch/router 2030 component.
[0040] Instead of a single modem (modem 2022 of FIG. 3) that
communicates with multiple encryption keys, this embodiment
includes two modems 2022 and 2012 and each modem may communicate
using a different encryption key to perform the logical isolation
of networks described above. Thus, modem 2022 may use the
encryption key of, and may communicate only with, the bypass device
100. Similarly, modem 2012 may use the encryption key associated
with power line modems of, and communicate only with, user devices
in the home. Additionally, because the two modems use different
encryption keys, they cannot communicate with each other. In
addition, with numerous encryption keys this embodiment may ensure
that devices in nearby customer premises (connected to the same LV
power line) cannot communicate (receive or transmit) data with
devices in the customer premises.
[0041] In a second embodiment, instead of using different
encryption keys the two power line interface circuits 2010 and 2020
may be configured to receive and transmit in different frequency
bands to perform the logical isolation of networks described above.
In this embodiment, the power line interface 2020 may not include
frequency translation and be configured to receive and transmit in
the 4-21 MHz band. Power line interface 2010 may include two
frequency translation circuits--one for upbanding the output of the
modem to the higher frequency band (e.g., 30-50 MHz) and one for
downbanding the input of the higher frequency to 4-21 MHz used by
the modem. Alternatively, the modem itself may communicate on 4-21
or 30-50 as selected by Processor 2040. In still another
embodiment, a natively upbanded modem chip may be used. Thus, one
frequency may be used to communicate with user devices and the
other for communicating with the bypass device.
[0042] In operation, the module 2000 works substantially the same
as the embodiment of FIG. 3 except that data received by the
processor 2040 from one modem (e.g., 2012) will be supplied to the
other modem (e.g. 2022) for transmission, if repeating is enabled.
This process is accomplished via Ethernet switch/router 2030. or
processor.
[0043] FIG. 5 illustrates another example embodiment of
communications module 2000, which includes filter 2005 for
substantially impeding data signals traversing the LV power line
conductors. Thus, filter 2005 provides isolation between the
internal and external networks. This example embodiment functions
in substantially the same manner as the embodiment of FIG. 4.
However, data signals received from the external LV power line
(e.g., from a bypass device 100) received at Port A typically will
not be received at Port B because they will be attenuated by the
filter 2005. Also, data signals received from the internal LV power
line (e.g., from a user device) received at Port B typically will
not be received at Port A because they will be attenuated by the
filter 2005. In addition, the filter 2005 may prevent transmissions
from one port from being received at the other port. Thus, the
filter 2005 serves to substantially isolate modem 2012 from modem
2022. Thus, this embodiment need not use multiple encryption keys
or different frequency bands to isolate the two networks. The RF
filter 2005 may be implemented in any suitable manner such as in a
separate meter collar or in the meter. Additionally, for many
implementations the RF filter 2005 may not need to filter one
hundred percent of the data signals. For example, even if the RF
block only filters data signals received from other devices (does
not sufficiently filter signals transmitted from modems 2012 and
2022) use of the RF block may improve communications (e.g., reduce
latency) as both modems may be able to receive data signals
simultaneously. Thus, addressing of data packets for only one of
the two modems and/or encryption (as described herein) may be used
in addition to the RF filter 2005.
[0044] In the embodiments disclosed, utility data such as power
usage data, gas usage data, water usage data and electric voltage
data, may be stored in memory of the module and transmitted to the
network element 1) periodically, 2) upon receiving a request to
transmit the data from the network element, 3) when memory in the
device reaches a threshold percentage of capacity, 4) upon a
triggering event such as an out of limit voltage measurement;
and/or 4) at the occurrence of other events. The device may also
store data from multiple meters (e.g., a gas, water, and power
meter) and may be connected to such other non-power meters via a
coaxial cable, a twisted pair, Ethernet cable, wirelessly, or other
suitable medium. In some instances, localized noise may increase
the noise floor at a device and degrade that device's ability to
receive data. Thus, it may be desirable to only repeat data
communications in one direction. Consequently, in some of the
embodiments disclosed herein and others, it may not be necessary to
repeat data in both directions. In other words, the device (or
module 2000) may be configured to repeat only upstream data (data
transmitted from the user device) or only downstream data (data
transmitted to the user device). The module 2000 may be configure
itself via channel testing and/or by receiving an appropriate
command.
[0045] In still another embodiment, the implementation of FIG. 5
may be modified to connect the interface 2010 to the internal
telecommunication network of the customer premises, such as a fiber
network, coaxial cable network, Ethernet, or twisted pair
network--instead of communicating the data over the internal power
line network. In such an embodiment the internal power line network
could be used as another local area network that is separate from
the internal telecommunications network and the RF filter 2005 may
provide isolation between the internal local area power line
network and the external access network. The connection to the
internal communications network may be via any suitable medium such
as those described above. Finally, in still another embodiment
modem 2012 may comprise a wireless modem (or wireless modem and
router) and antenna for providing communications with a wireless
network in the customer premises or wireless enabled user devices
and other meter or utility devices (e.g., gas meters, water meters,
other power meters, direct load control switch, and/or utility
distribution automation equipment) via an IEEE 802.11 protocol. In
addition to repeating user data, the present invention may be used
to repeat utility data for other utility devices such gas meters,
water meters, other power meters, direct load control switches, and
utility distribution automation equipment. While some of the
example embodiments disclosed herein employ a first and second
encryption key, other embodiments may use three, four or more keys.
For example, communications with each user device in the customer
premises may employ a different key and/or communications with an
internal or external low voltage repeater may employ a different
key. In some embodiments, the processor described herein may be the
processor of the meter itself, which shares task between
controlling utility data collection and communication functions.
Alternately, some embodiments may not employ a processor and simply
have one or two modems that receive and transmit data when data is
received.
[0046] Finally, the type of data signals communicated via the MV
and LV power lines can be any suitable type of data signal. The
type of signal modulation used can be any suitable signal
modulation used in communications (Code Division Multiple Access.
(CDMA), Time Division Multiple Access (TDMA), Frequency Division
Multiplex (FDM), Orthogonal Frequency Division Multiplex (OFDM),
and the like). OFDM may be used for one or both of the LV and MV
power lines, including HomePlug 1.0, HomePlug Turbo or HomePlug AV
data signals. A modulation scheme producing a wideband signal such
as CDMA or OFDM that is relatively flat in the spectral domain may
be used to reduce radiated interference to other systems while
still delivering high data communication rates. Thus, the example
communication module described above may be used with frequency
division multiplexed communication systems or time division
multiplexed communication systems.
[0047] In addition, instead of using OFDM signals on the MV power
line or LV power line, an alternate embodiment of a PLCS system may
use ultra wideband signals to provide communications over the MV
and/or LV power lines.
[0048] It is to be understood that the foregoing illustrative
embodiments have been provided merely for the purpose of
explanation and are in no way to be construed as limiting of the
invention. Words used herein are words of description and
illustration, rather than words of limitation. In addition, the
advantages and objectives described herein may not be realized by
each and every embodiment practicing the present invention.
Further, although the invention has been described herein with
reference to particular structure, materials and/or embodiments,
the invention is not intended to be limited to the particulars
disclosed herein. Rather, the invention extends to all functionally
equivalent structures, methods and uses, such as are within the
scope of the appended claims. Those skilled in the art, having the
benefit of the teachings of this specification, may affect numerous
modifications thereto and changes may be made without departing
from the scope and spirit of the invention.
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