A photovoltaic, PV, module level monitoring system (1) comprising a photovoltaic array (PVA) including at least one photovoltaic string (PVS) comprising photovoltaic modules, PVM, (5) each having a module level device, MLD, (4) adapted to monitor and/or to control the associated photovoltaic module, PVM, (5), wherein each module level device, MLD, (4) comprises a transceiver adapted to communicate with a transceiver of a base station (2) of an inverter (6) connected to said photovoltaic array (PVA), wherein the transceivers are coupled by associated duplexer circuits (7) to a DC power network comprising power cables (3) connecting the photovoltaic modules, PVM, (5) of the at least one photovoltaic string (PVS) of said photovoltaic array (PVA) with the base station (2) of the inverter (6), wherein a signal amplitude of a communication signal, CS, transmitted by a transceiver via its associated duplexer circuit (7) is adjusted automatically depending on a monitored impedance, Z.sub.PV, of the respective photovoltaic array (PVA).

Aspects of the subject disclosure may include, for example, a surveying system operable to receive a plurality of electromagnetic waves via a guided wave transceiver that include environmental data collected via a plurality of sensors at a plurality of remote sites. Weather pattern data is generated based on the environmental data. Other embodiments are disclosed.

A communication system can include a first transceiver and a second transceiver that can communicate digital baseband data via a direct current (DC) power line bus in the wellbore. One or more of the transceivers includes a demodulator for demodulating the digital baseband data received from the DC power line bus into multiple digital data streams, and includes a digital processor for filtering and applying error correction to the digital data streams to produce a decoded digital data stream.

Activity sensing in the home has a variety of important applications, including healthcare, entertainment, home automation, energy monitoring and post-occupancy research studies. Many existing systems for detecting occupant activity require large numbers of sensors, invasive vision systems, or extensive installation procedures. Disclosed is an approach that uses a single plug-in sensor to detect a variety of electrical events throughout the home. This sensor detects the electrical noise on residential power tines created by the abrupt switching of electrical devices and the noise created by certain devices while in operation. Machine learning techniques are used to recognize electrically noisy events such as turning on or off a particular light switch, a television set, or an electric stove. The system has been tested to evaluate system performance over time and in different types of houses. Results indicate that various electrical events can be learned and classified with accuracies ranging from 85-90%.

A system (and system controller) has powering of, and communication with, a set of fixtures using an AC cable having a power line (e.g. a mains live wire), a reference line (e.g. a mains neutral wire) and a data line. Fixtures are at different positions along the cable, each powered by the local voltage difference between the power line and the reference line. A system controller provides a data signal over the data line, wherein the data signal for a fixture is defined by the local voltage difference between the data signal on the data line and the reference line (or power line). In order to compensate for voltage drops, a compensation circuit adds a voltage offset waveform to the data signal which is dependent on the overall set of positions of the fixtures. This enables an increased number of fixtures and/or reach of the fixtures connected to the system controller.

A photovoltaic, PV, module level monitoring, MLM, system (1) comprising a base station, BS, (2) connected by means of power cables (3) to module level devices, MLD, (4) which are provided to monitor and/or to control associated photovoltaic modules, PVMs, (5), wherein the base station, BS, (2) comprises a base station transmitter (2A) adapted to transmit Rapid Shut Down, RSD, control signals, CS, in predefined time slots, TS.sub.CS, in a downlink channel, DL-CH, through said power cables (3) to said module level devices, MLDs, (4) and a base station receiver (2B) adapted to receive monitoring signals, MS, generated by said module level devices, MLDs, (4) through said power cables (3) within time slots, TS.sub.MS, via an uplink channel, UL-CH, assigned to the module level devices, MLDs, (4).

A first mobile device including a connection terminal configured to electrically connect to a second mobile device, a variable impedance device connected to the connection terminal, the variable impedance device configured to vary an impedance, processing circuitry configured to determine a power line communication (PLC) mode between the first mobile device and the second mobile device to be one of a low-speed PLC mode or a high-speed PLC mode, and control the impedance of the variable impedance device according to the determined PLC mode, and a PLC modem configured to receive power from the second mobile device or communicate data with the second mobile device based on the determined PLC mode.

The invention relates in particular to a method executed by a control device, for a mesh communication network, allowing selection of an optimum frequency band, the method comprising the steps of determining network quality information, if the quality information is below a first threshold, then: sending, to each device in the network, a message comprising an instruction to perform a frequency band quality test, collecting, at the end of the quality test, for each device, quality data for each frequency band, determining, for each frequency band, a quality indicator, and selecting a so-called optimum frequency band as being the frequency band associated with the best indicator, when the so-called optimum frequency band is different from the frequency band used, then sending, to each device, an instruction to use the so-called optimum frequency band.

Aspects of the subject disclosure may include, a system that facilitates detecting first electromagnetic waves propagating along a transmission medium are experiencing a first propagation loss, inducing second electromagnetic waves along the transmission medium to mitigate the first propagation loss, detecting that the second electromagnetic waves are experiencing a second propagation loss and inducing third electromagnetic waves along the transmission medium to mitigate the second propagation loss. To reduce radiation losses when transitioning from the first electromagnetic waves to second electromagnetic waves and transitioning from the second electromagnetic waves to the third electromagnetic waves, the system can be further adapted to use differing criteria for each transition. Other embodiments are disclosed.

A first mobile device including a connection terminal configured to electrically connect to a second mobile device, a variable impedance device connected to the connection terminal, the variable impedance device configured to vary an impedance, processing circuitry configured to determine a power line communication (PLC) mode between the first mobile device and the second mobile device to be one of a low-speed PLC mode or a high-speed PLC mode, and control the impedance of the variable impedance device according to the determined PLC mode, and a PLC modem configured to receive power from the second mobile device or communicate data with the second mobile device based on the determined PLC mode.