Aspects of the subject disclosure may include, for example, a system for detecting an accumulation of a liquid on a transmission medium that may interfere with the propagation of guided electromagnetic waves on a surface of the transmission medium, and directing a device to remove at least a portion of the liquid accumulating on the surface of the transmission medium to mitigate the interference. Other embodiments are disclosed.

Aspects of the subject disclosure may include, for example, a transmission system having a coupling device, a bypass circuit, a memory and a processor. The coupling device can facilitate transmission or reception of electromagnetic waves that propagate along a surface of a transmission medium. The memory can store instructions, which when executed by the processor, causes the processor to perform operations including restarting a timer to prevent the bypass circuit from disabling the transmission or reception of electromagnetic waves by the coupling device. Other embodiments are disclosed.

In accordance with one or more embodiments, a system includes an impedance matching circuit that includes one or more adjustable circuit elements, wherein the impedance matching circuit receives an input signal and generates an output signal in response to the input signal. A guided wave launcher is configured to generate, in response to the output signal, a first guided electromagnetic wave along a surface of a transmission medium, wherein the first guided electromagnetic wave propagates along the surface of the transmission medium without requiring an electrical return path. A controller is configured to generate one or more control signals in response to a channel quality indicator, wherein the one or more control signals adjust the one or more adjustable circuit elements of the impedance matching circuit, wherein adjustment of the one or more adjustable circuit elements facilitates reducing an impedance mismatch of the guided wave launcher.

A main power line (+ and lines) is coupled to a power supply, for example a car battery, grounded to a vehicle chassis. Positive and negative main power lines are coupled to a power line gateway module, and spliced to carry power for a segment, until receiving, by splices, RF power line communications. The main power lines, now carrying power and RF power line communications are then coupled to remote modules. RF power line communication carries signal from the power line gateway module to a impedance matching network or a transformer are used to match impedances.

The present invention is directed to polyisocyanates and polyurethanes derived therefrom. In various embodiments, the present invention provides polyisocyanates, methods of making the polyisocyanates from fused bicyclic alcohols, polyurethanes, and methods of making the polyurethanes from the polyisocyanates.

Aspects of the subject disclosure may include, for example, a transmission medium for propagating electromagnetic waves. The transmission medium can include a plurality of cores for selectively guiding an electromagnetic wave of a plurality of electromagnetic waves longitudinally along each core, and a shell surrounding at least a portion of each core for reducing exposure of the electromagnetic wave of each core. 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.

A welding system is provided. The welding system includes a low power transceiver configured to be coupled to a weld cable. The low power transceiver includes a low power transmitter, a low power receiver, and a first processor. The low power receiver is configured to transmit one or more unmodulated tones through the weld cable to a welding power supply. The low power receiver is configured to receive the one or more unmodulated tones through the weld cable from the welding power supply. The first processor is configured to determine one or more channel equalization filter coefficients related to the weld cable corresponding to a distortive characteristic of the weld cable.

In accordance with one or more embodiments, an antenna system includes a dielectric antenna having a feed point, wherein the dielectric antenna is a single antenna. At least one cable having a plurality of conductorless dielectric cores is coupled to the feed point of the dielectric antenna, wherein electromagnetic waves that are guided by differing ones of the plurality of conductorless dielectric cores to the dielectric antenna result in differing ones of a plurality of antenna beam patterns.

Systems, methods, and apparatuses for improved powerline communication (PLC) are described. In one embodiment, a system comprises power down hardware coupled to internal wiring of a premises to selectively power down a portion of the internal wiring on request, and at least one hardware device to transmit a request to the power down hardware to selectively power down a portion of the internal wiring on request and to transmit data using power line communication hardware of the at least one hardware device while the portion of the internal wiring is powered down.