Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for varying symbol amplitude. In one aspect, a system includes a symbol generator that includes a waveform generator configured to output waveforms at a plurality of selectable fundamental frequencies and with a selectable duty cycle. The symbol generator can also include a bandpass filter having a pass-band that corresponds to a communications channel of a communications network. The system can also include data processing apparatus operable to interact with the symbol generator and further operable to determine that at least a threshold number of endpoints that receive symbols from the symbol generator are experiencing a same type of transmission error. In response to the determination, the data processing apparatus can cause the waveform generator to adjust at least one of the fundamental frequency or a duty cycle of the waveforms.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for detecting grid events. In one aspect, a method includes receiving signal characteristic data that specify signal characteristic values for signals that are received over each of a plurality of communications channels of a power line communications network. A determination is made that the signal characteristic values for the signals that are received over at least one of the communications channels are outside of a baseline signal value range. An endpoint that communicates over the at least one communications channel is identified, and a determination is made that a set of the signal characteristic values for the identified endpoint matches one of a plurality a grid event signatures for the identified endpoint. Data that identify the endpoint and a particular grid event that is represented by the matched grid event signature are provided.

Abstract: Disclosed are various embodiments of an input signal combiner. In one embodiment, a receive stage receives a multi-phase waveform and separates the multi-phase waveform into a plurality of waveforms. Analog-to-digital converters convert the plurality of analog waveforms into at least one digital signal. At least one gain stage adjusts an amplitude of each of the digital signals and combines the amplitude adjusted digital signals into at least one gain adjusted combined signal. A signal extraction stage extracts an inbound signal from the at least one gain adjusted combined signal according to a demodulation scheme.

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: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for communicating using harmonic tones. In one aspect, a method includes receiving harmonic tones that represent data being reported by a node that generated the harmonic tones; selecting data that are represented by each of the harmonic tones; and providing the data that are represented by the harmonic tones.

Abstract: Disclosed are various embodiments of a programmable slicer in a digital signal processing system and/or software radio system. In one embodiment, a plurality of demodulation schemes and a plurality of channel definitions are stored in a channel allocation table. An analog waveform is received and converted into at least one digital waveform. A specified frequency range is isolated from the at least one digital waveform. The magnitude of tones within the specified frequency range is measured and stored in a signal magnitude table. Symbols and/or bits are decoded from the signal magnitude table by applying a demodulation schemes and channel definitions to the magnitudes stored in the signal magnitude table.

Abstract: Disclosed are various embodiments of systems and methods for relative phase shift keying. In one embodiment, an analog waveform is converted to digital signals. A specified frequency range is isolated and the magnitudes of tones corresponding to a channel are measured. The relative phase of a subset of the tones having the greatest magnitude is measured and a relative phase component is generated. At least one symbol is associated with the subset of tones and the relative phase component.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for. In one aspect, a method includes detecting, by an end point, a first broadcast message specifying a first network identifier for a first PLC network and a first unique substation identifier for a first substation processing unit that belongs to the first PLC network. Data is encoded with the first network identifier and the first unique substation identifier and the encoded first data is transmitted to the first substation processing unit.

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: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for detecting a power outage. In one aspect, a status request requesting a status of a portion of a power distribution network is received, where the request includes a reference to a power meter that is located within the portion of the network. In response to the status request, a block of communications channels is selected, where the block includes a target communications channel over which a signal corresponding to the referenced power meter is received. In turn, an amplitude of the signal being received over the target communications channel is obtained. A determination is made whether the amplitude of the signal is less than an outage threshold and a status notification is provided that specifies the status of the portion of the power distribution network for which the status has been requested.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for identifying network events. In one aspect, a method includes monitoring signal characteristic values for signals transmitted over a communications channel of a power line communications system and determining that a signal level value for the channel is less than a threshold signal level value for the channel. In response to determining that the signal level value for the channel is less than the threshold signal level value for the channel, computing a signal to noise ratio for the communications channel and determining that the signal to noise ratio for the channel exceeds a threshold value. In response to determining that the signal to noise ratio for the communications channel exceeds the threshold value, storing data received over the communications channel as valid data.

Abstract: A network status is determined based on channel data specifying at least one channel characteristic of a communications channel. Changes in various channel characteristics are indicative of changes in a status of a distributed network. Therefore, these channel characteristics can be monitored over time to identify changes to the status of the distributed network. Changes to channel characteristics can be identified based on normalized channel data that is normalized relative to reference channel data. Status scores are generated based on the normalized channel data. The status scores are, in turn, normalized for channels that are identified as valid channels. The normalized status scores are adjusted based on variations of the channel data and the network status is identified based on status score variations. Status data identifying the network status is generated based on the status of the network.

Abstract: Disclosed are various embodiments for arbitration of memory transfers in a digital signal processing system. In one embodiment, a digital signal processing system includes a plurality of DSP's having an external memory. The DSP's are further configurable to act as a master processor and a slave processor relative to another DSP. The system also includes an arbiter configured to maintain DSP status data and arbitrate requests between master processors and slave processors in the system.

Abstract: Disclosed are various embodiments of systems and methods for relative phase shift keying. In one embodiment, an analog waveform is converted to digital signals. A specified frequency range is isolated and the magnitudes of tones corresponding to a channel are measured. The relative phase of a subset of the tones having the greatest magnitude is measured and a relative phase component is generated. At least one symbol is associated with the subset of tones and the relative phase component.

Abstract: Included are embodiments for providing communications services. At least one embodiment includes a first communications component configured to receive data from a first communications device and a second communications component configured to send at least a portion of the received data to a second communications device.

Abstract: Disclosed are various embodiments of an input signal combiner. In one embodiment, a receive stage receives a multi-phase waveform and separates the multi-phase waveform into a plurality of waveforms. Analog-to-digital converters convert the plurality of analog waveforms into at least one digital signal. At least one gain stage adjusts an amplitude of each of the digital signals and combines the amplitude adjusted digital signals into at least one gain adjusted combined signal. A signal extraction stage extracts an inbound signal from the at least one gain adjusted combined signal according to a demodulation scheme.

Abstract: Disclosed are various embodiments of a programmable slicer in a digital signal processing system and/or software radio system. In one embodiment, a plurality of demodulation schemes and a plurality of channel definitions are stored in a channel allocation table. An analog waveform is received and converted into at least one digital waveform. A specified frequency range is isolated from the at least one digital waveform. The magnitude of tones within the specified frequency range is measured and stored in a signal magnitude table. Symbols and/or bits are decoded from the signal magnitude table by applying a demodulation schemes and channel definitions to the magnitudes stored in the signal magnitude table.

Abstract: Disclosed are various embodiments for arbitration of memory transfers in a digital signal processing system. In one embodiment, a digital signal processing system includes a plurality of DSP's having an external memory. The DSP's are further configurable to act as a master processor and a slave processor relative to another DSP. The system also includes an arbiter configured to maintain DSP status data and arbitrate requests between master processors and slave processors in the system.

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.