A transmission circuit includes a first transmitter and a second transmitter. The first transmitter turns OFF first transistors when a transmission data is in a high level, and turns ON the first transistors when the transmission data is in a low level. When a permission signal is in the high level, the second transmitter turns ON the second transistors when the transmission data is in the high level, and turns OFF the second transistors when the transmission data is in the low level. Diodes are set to suppress an amplitude of a differential signal in an ON time of the second transistors more than an amplitude of a differential signal in an ON time of the first transistors, to suppress ringing and radiation noise.

Systems and methods for application profiles and device classes in power line communications (PLCs) are described. In some embodiments, a PLC device has the device class defined by a PHY layer and may include a processor and a memory coupled to the processor. The memory may be configured to store program instructions, which may be executable by the processor to cause the PLC device to communicate with a higher-level PLC apparatus over a power line using a frequency band. The frequency band may be selected based upon an application profile and/or a device class associated with the PLC device. In some implementations, the higher-level PLC apparatus may include a PLC gateway or a data concentrator, and the PLC device may include a PLC modem or the like. Examples of application profiles include access communications, in-premises connectivity, AC charging, and/or DC charging. Device classes may represent a minimum communication data rate and/or an operating frequency band restriction of the PLC device.

To provide a circuit module, a bicycle electric component, and a communication system that are easily matched to a communication system that uses power line communication, a circuit module is configured to be mounted on a bicycle electric component. The circuit module includes a first circuit board, a communication converter configured to convert between information appropriate to power line communication and information appropriate to communication other than the power line communication and mounted on the first circuit board, and a plurality of first terminals formed on the first circuit board. The plurality of first terminals is connected to a second circuit board included in the electric component.

Embodiments of the invention provide multiple cyclic prefix lengths for either both the data-payload and frame control header or only the data payload. Frame control header (FCH) and data symbols have an associated cyclic prefix. A table is transmitted in the FCH symbols, which includes a cyclic prefix field to identify the cyclic prefix length used in the data payload. A receiver may know the cyclic prefix length used in the FCH symbols in one embodiment. In other embodiments, the receiver does not know the FCH cyclic prefix length and, therefore, attempts to decode the FCH symbols using different possible cyclic prefix lengths until the FCH symbols are successfully decoded.

In a powerline communications (PLC) network having a first node and at least a second node on a PLC channel utilizing a band including a plurality of tones, based on at least one channel quality indicator (CQI), the first node allocates for a tone map response payload only a single (1) power control bit for each of a plurality of subbands having two or more tones. The power control bit indicates a first power state or a second power state. The first node transmits a frame including the tone map response payload to the second node. The second node transmits a frame having boosted signal power for the tones in the subbands which have the first power state compared to a lower signal power for the tones in the subbands which have the second power state.

A method of encoding a first bit and a second bit for transmission on a transmission band is provided. The method includes: mapping, via a mapping component, the first bit and the second bit into a first symbol; mapping, via the mapping component, the first bit and the second bit into a second symbol; dividing, via a dividing component, the transmission band into subcarriers; allocating, via an allocating component, the first symbol to a first subcarrier of the subcarriers; allocating, via the allocating component, the second symbol to a second subcarrier of the subcarriers; and differentially encoding, via a differential encoder, the first symbol and the second symbol.

A system with which any abnormality can be easily found is provided. A system includes: a first modulator that generates a control signal and modulates an input signal in accordance with the generated control signal, to control luminance of a first light source that emits light according to the modulated input signal, the first modulator outputting the control signal; a second modulator that acquires the control signal output from the first modulator and modulates an input signal in accordance with the control signal, to control luminance of a second light source that emits light according to the modulated input signal, the second modulator outputting the control signal. The first modulator generates, as a light ID signal, a control signal for transmitting a visible light signal by luminance variations of the first light source, and acquires a light information signal being the control signal output from the second modulator.

Multicast transmissions do not allow for individual receivers to acknowledge that data was received by each receiver in the network. This is not acceptable for isochronous systems that require specific levels of QoS for each device. A multimedia communications protocol supports using multicast transmissions (one-to-many) in multimedia isochronous systems. A transmitter establishes a Multi-ACKed Multicast protocol within which a group of receiving devices can acknowledge the multicast transmission during a multi-acknowledgment period.

A system for transmitting power and data, particularly including a half-wave control, includes a control unit connected to grid phases, the system having a phase-failure detection device which has bistable multivibrators, especially bistable multivibrators assigned to a respective grid phase. Each bistable multivibrator has an input for setting and an input for resetting, one of the inputs being connected to a digitizing device for digitizing the positive half-waves of a respective grid phase, the other of the inputs being connected to a digitizing device for digitizing the negative half-waves of a respective grid phase. The effective value of the output voltage of the bistable multivibrator is compared by a comparison device to a threshold value to detect a phase failure.

Built-in instrumentation for power measurement integrating power monitoring, delivery and management, power safety, and automation control.