Aspects of the subject disclosure may include, for example, a system for receiving first electromagnetic waves via a transmission medium without utilizing an electrical return path, and inducing second electromagnetic waves at an interface of the transmission medium without the electrical return path. In an embodiment, the first and second electromagnetic waves have a non-optical frequency range. Other embodiments are disclosed.

A method for delivering a communication signal is disclosed. The method includes receiving, at an optical transceiver, an optical communication and constructing, at a baseband integrated circuit in communication with the optical transceiver, a radio frequency communication (e.g., the intermediate frequency data and control signals) based on the optical communication. The method also includes transmitting the radio frequency communication from a Sommerfeld-Goubau launcher in communication with the baseband integrated circuit as a surface wave along a power line to a strand mount device disposed on the power line. The strand mount device is configured to receive the radio frequency communication and wirelessly transmit the radio frequency communication (e.g., via a wireless link) to a user device.

The present invention relates to a system (100) for supplying low-voltage DC power to at least one electronic communication device (3;6) in a power line carrier communication system furthermore including a power line carrier coupler comprising a coupling capacitor (10) electrically linked to a medium-voltage line (8) of a power distribution network. According to the invention, the system (100) comprises means (15) for generating a first low DC voltage value based on a current-to-voltage conversion of the leakage current related to said coupling capacitor (10), said first low DC voltage value being able to act as power supply to at least one active electronic component (13) of said at least one electronic communication device (3;6).

An isolated signal transmission apparatus isolatingly transmits, from a control-side apparatus to a control target apparatus, an electric signal obtained by superimposing a communication signal on a direct-current signal. The apparatus includes a lower limiter circuit configured to output, to the control target apparatus, a direct-current signal, whose value is a predetermined lower limit value, if a value of the direct-current signal from the control-side apparatus is less than the predetermined lower limit value.

A method and system for sending a repetitive permissive guard signal from an electrical power substation to a distributed generation site over existing medium voltage distribution lines to detect an islanding condition and apply transfer trip protection is disclosed. The permissive guard signal causes a receiver at the distributed generation site to control a recloser at the distributed generation site. Loss of the signal at the receiver device causes the tripping of the recloser at the distributed generation site in less than two seconds. The tripping of the recloser physically disconnects the distributed generation site from the electric power grid. The coupling to the medium voltage distribution lines can be implemented via a single phase-to-ground coupling or via a phase-to-phase differential coupling for multi-phase medium voltage distribution lines.

Embodiments of this application disclose a method, an apparatus, and a system for information transmission in a PLC network. A switch control apparatus in embodiments of this application includes a switch and a coupling circuit. The coupling circuit is connected in parallel to two ends of the switch. When the switch is open, the coupling circuit transmits a first power line communication (PLC) signal to a gateway device. In embodiments of this application, when the switch is open, the PLC signal may be sent to the gateway device and information such as power off and tripping may be reported to the gateway device.

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.

A powerline communication (PLC) device can be configured to execute functionality for zero cross sampling and detection. When the PLC device is directly coupled to a high-voltage PLC network, the PLC device can comprise printed safety capacitors in series with a high-voltage input AC powerline signal to safely couple the high-voltage AC powerline signal to the low-voltage processing circuit. The PLC device can also comprise an ADC to sample a scaled AC powerline signal and to obtain zero cross information. When the PLC device is part of an embedded PLC application, dynamic loading can affect the integrity of a low voltage zero cross signal that is used to extract zero cross information. After digitizing the zero cross signal, the PLC device can execute functionality to minimize/eliminate voltage drops caused by dynamic loading and obtain the zero cross information.

A data transmission system including an emitting device, a receiving device and a communication link, wherein the emitting device includes: a radio frequency emitter connected to the communication link; a power line connected to the communication link at a connection point, wherein the power line is brought to a supply voltage; and a capacitive coupling component connected between the radio frequency emitter and the connection point, wherein the receiving device includes: a radio frequency receiver connected to the communication link for receiving the radio frequency signal; a power line connected to the communication link at a connection point; and a capacitive coupling component connected between the connection point and the radio frequency receiver, wherein the capacitive coupling components transmit the radio frequency signal and block the supply voltage.

Aspects of the subject disclosure may include, for example, different groups of network devices mounted on utility poles. The different groups of network devices can be arranged along different paths. A communication path for transmitting wireless signals can alternate between the different groups of network devices. Other embodiments are disclosed.