Abstract: An apparatus is provided for data communication over power lines in a PLC system. The apparatus includes a data-coupling circuit configured to provide data to the power lines for transmission. The data-coupling circuit includes a DC-isolation circuit configured to isolate circuitry of the data-coupling circuit from the power lines. The apparatus also includes a feedback circuit connected to the DC-isolation circuit. The feedback circuit has a power-tap circuit on an endpoint side of the feedback circuit. The power-tap circuit is configured to provide a feedback signal indicative of an estimate of an amount of power, current, and/or voltage provided from the data-coupling circuit through the DC-isolation circuit and to the power lines. Based on the feedback the signal, the strength of a transmitted may be adjusted (e.g., to maintain constant signal strength).

Abstract: In a power-line communication system, a data processing electronic circuitry can receive a plurality of symbols from a plurality of endpoint circuits and over a plurality of communications channels on power lines in a power-line communication system. A first symbol of the plurality of symbols can be decrypted using a first decryption key that is assigned to a first endpoint circuit. From the first decryption, a first measure of error is computed that includes a first bit error rate. The first symbol is decrypted using a second decryption key that is assigned to a second endpoint circuit. From the second decryption, a second measure of error is computed that includes a second bit error rate. The first and second bit error rates are compared to a threshold error measure to determine validity.

Abstract: Aspects of the present disclosure are also directed towards a method that includes maintaining a transmission period which has a start time and an end time synchronized to metrological time. Further, this method, in response to the start time, begins transmission of a frame, which includes a plurality of symbols. This transmission occurs over power distribution lines that carry power using alternating current (AC). This method also includes synchronizing a transmission time for each symbol of the plurality of symbols according to a time-based parameter of the AC. In response to reaching an end of the frame, a synchronization symbol period is determined for a synchronization symbol, as a function of the transmission times, for the plurality of symbols and time from the end of the frame to the end time. The synchronization symbol is then transmitted on the power distribution lines.

Abstract: Particular embodiments are directed towards a method for communicating time-based data in a power line communication system. The communication system utilized in the method includes: a command center; a collector device; and a plurality of endpoint devices. The method includes communicating, from the collector device, downstream data to the plurality of endpoint devices. This downstream communication utilizes a communication protocol that is relative to a collector network time, and is over a set of power distribution lines carrying alternating current (AC). The collector network time uses the local oscillator. The AC zero-crossing event can be used as a time base for other versions of the network time. Conceptually, the AC can be thought of as acting as a reference clock for maintaining these other network times, although the clocking function can be carried out in the digital realm, e.g., using a digital-signal processor (DSP).

Abstract: Aspects of the present disclosure are directed toward a system that includes a plurality of endpoint devices. Each endpoint device can be configured and arranged to monitor a plurality of communication channels carried over power distribution lines for data communications. The endpoint can detect setup communications that contain an endpoint identifier (ID) matching the endpoint. The endpoint then stores or assigns the organization ID (obtained from the detected communications) to itself. The endpoint configures itself to respond to subsequent operational communications based upon the organization ID. A command center is configured and arranged to transmit setup communications to endpoint devices. The setup communications can include one or more endpoint identifiers and the organization ID. The command center can also transmit operational communications to the plurality endpoint devices, the operational communications including the organization ID.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for transmitting data. In one aspect, a method obtains a baseline data rate for transmissions from a node that are received over a channel of a power line communications system and a set of available modulation techniques for the node. The set of available modulation techniques can include at least two modulation techniques with which the node is configured to encode data that are transmitted over the channel. Using the set of available modulation techniques, a modulation technique that is capable of providing at least the baseline data rate with at least a threshold confidence for the node is selected. In turn, data is provided to the node specifying the selected modulation technique.

Abstract: In one or more embodiments, a data processing apparatus is configured to receive data symbols transmitted from one or more endpoint devices. Each of the data symbols is transmitted in a respective temporal position assigned for communication by one of the plurality of endpoints. The data processing apparatus is configured to recover data from two or more transmission(s)/retransmission(s) (of the same data) that are received in error and have different temporal positions. The corresponding data symbols in error are phase-aligned per a common reference point and energy is accumulated therefrom. The data processing apparatus discerns correct data values from the accumulated energy.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for authenticating a communications source. In one aspect, a method includes decrypting a symbol that was received over a particular communications channel. The symbol is decrypted using a decryption key that is assigned to a particular endpoint that is assigned the particular communications channel. A measure of error is computed for the decrypted symbol. In turn, a determination is made whether the measure of error exceeds a threshold error measure. If the measure of error does not exceed the threshold error measure the decrypted symbol is identified as a valid symbol transmitted by the particular endpoint, and logged as such. If the measure of error exceeds the threshold error measure, the decrypted symbol is identified as a symbol from a different endpoint.

Abstract: In one or more embodiments, a data processing apparatus is configured to receive data symbols transmitted from one or more endpoint devices. Each of the data symbols is transmitted in a respective temporal position assigned for communication by one of the plurality of endpoints. The data processing apparatus is configured to recover data from two or more transmission(s)/retransmission(s) (of the same data) that are received in error and have different temporal positions. The corresponding data symbols in error are phase-aligned per a common reference point and energy is accumulated therefrom. The data processing apparatus discerns correct data values from the accumulated energy.

Abstract: Aspects of the present disclosure are directed towards communications over current-carrying power distribution lines. In accordance with one or more embodiments, respective sets of utility-based data indicative of a reading of utility usage taken at different times are communicated. First sets of the data corresponding to readings taken during a first time period are communicated and, thereafter, second sets of the data corresponding to readings taken during a second time period are communicated and interleaved with portions of error correction code (ECC) data. Prior to receiving at least some of the ECC data, the first sets of data are interpreted and access is provided to the interpreted data. After all of the ECC data has been received, the ECC data is used to verify the first sets of data, correct the first sets of data, and access to is provided to the verified first sets of data.

Abstract: Aspects of the present disclosure are also directed towards a method that includes maintaining a transmission period which has a start time and an end time synchronized to metrological time. Further, this method, in response to the start time, begins transmission of a frame, which includes a plurality of symbols. This transmission occurs over power distribution lines that carry power using alternating current (AC). This method also includes synchronizing a transmission time for each symbol of the plurality of symbols according to a time-based parameter of the AC. In response to reaching an end of the frame, a synchronization symbol period is determined for a synchronization symbol, as a function of the transmission times, for the plurality of symbols and time from the end of the frame to the end time. The synchronization symbol is then transmitted on the power distribution lines.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for transmitting data. In one aspect, a method obtains a baseline data rate for transmissions from a node that are received over a channel of a power line communications system and a set of available modulation techniques for the node. The set of available modulation techniques can include at least two modulation techniques with which the node is configured to encode data that are transmitted over the channel. Using the set of available modulation techniques, a modulation technique that is capable of providing at least the baseline data rate with at least a threshold confidence for the node is selected. In turn, data is provided to the node specifying the selected modulation technique.

Abstract: Aspects are directed to communicating data over power distribution lines carrying alternating current, using a communication protocol for communicating data between endpoint devices and an upstream data-collecting device. From first symbols having a plurality of bits, at least two second symbols are generated, the second symbols respectively including different subsets of the bits in the first symbol. Each first symbol is split into second symbols having a predefined bit size for an encoding operation that operates on entire symbols having the predefined bit size (e.g., smaller than the bit size of the first symbols). The second symbols are encoded and combined according to the communication protocol. The encoded symbols are communicated over the power distribution lines based on timing indicated at least in part by the alternating current.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for dynamically selecting symbol periods for communications signals and recovering symbols from the communications signals. In one aspect, a method includes receiving a plurality of communications signals over a plurality of different communications channels and determining symbol period end times for the communications signals. A determination is made that a present time is coincident with an end of a sample period for the communications signals and that an end of the symbol period for the communications signals received over at least one of the communications channels is coincident with the present time. In turn, data are provided that represent a symbol received over each communications channel for which an end of the symbol period is coincident with the present time.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for authenticating a communications source. In one aspect, a method includes decrypting a symbol that was received over a particular communications channel. The symbol is decrypted using a decryption key that is assigned to a particular endpoint that is assigned the particular communications channel. A measure of error is computed for the decrypted symbol. In turn, a determination is made whether the measure of error exceeds a threshold error measure. If the measure of error does not exceed the threshold error measure the decrypted symbol is identified as a valid symbol transmitted by the particular endpoint, and logged as such.

Abstract: Aspects of the present disclosure are also directed towards a method that includes maintaining a transmission period which has a start time and an end time synchronized to metrological time. Further, this method, in response to the start time, begins transmission of a frame, which includes a plurality of symbols. This transmission occurs over power distribution lines that carry power using alternating current (AC). This method also includes synchronizing a transmission time for each symbol of the plurality of symbols according to a time-based parameter of the AC. In response to reaching an end of the frame, a synchronization symbol period is determined for a synchronization symbol, as a function of the transmission times, for the plurality of symbols and time from the end of the frame to the end time. The synchronization symbol is then transmitted on the power distribution lines.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for transmitting data. In one aspect, a method obtains a baseline data rate for transmissions from a node that are received over a channel of a power line communications system and a set of available modulation techniques for the node. The set of available modulation techniques can include at least two modulation techniques with which the node is configured to encode data that are transmitted over the channel. Using the set of available modulation techniques, a modulation technique that is capable of providing at least the baseline data rate with at least a threshold confidence for the node is selected. In turn, data is provided to the node specifying the selected modulation technique.

Abstract: A system for communicating data over power utility lines includes a plurality of endpoint devices. The endpoint devices can have modulation circuits configured and arranged to modulate data using multiple-orthogonal frequency sub-channels. The endpoint devices can also have a power line interface circuit configured and arranged to transmit the modulated data over a power utility line. A detection module can be configured and arranged to detect undesirable post modulation of a communication from one of the plurality of endpoint devices and to generate a signal responsive to the detected post modulation. The endpoint devices can then set a spacing between the multiple orthogonal frequency sub-channels in response to the signal responsive to the detected post modulation.

Abstract: Disclosed are various embodiments for dividing workload in a digital signal processing system. In one embodiment, the system includes at least one analog-to-digital converter configured to receive a three phase analog waveform and a digital waveform. The system can also include a first DSP configured to interface with an external computer and a second DSP configured to receive the digital waveform and isolate a specified frequency range. The system can also include a plurality of DSP's configured to extract specified channels from the specified frequency range and output the extracted channel data.

Abstract: A load control device is directly connected to a power utility line carrying electrical power using alternating current (AC) and to a load provided by a device located at premises. At the load control device, values are monitored for one or more load-responsive parameters of the electrical power over a period of time. A nominal value is determined for each of the one or more load-responsive parameters based upon the monitored values over the period of time. Threshold values are determined for the one or more load-responsive parameters based upon an acceptable deviation from the corresponding nominal value. A load-responsive parameter is detected as being outside of the threshold values. The load control device is then used to interrupt the providing of power to the load in response to the one or more load-responsive parameters being detected as being outside of the threshold values.