Embodiments include methods of powerline communications using a preamble with band extension is provided. A method may include receiving a packet data unit PDU. Bit-level repetition is applied to at least a portion of the PDU to create a repeated portion. Interleaving is performed per a subchannel. Pilot tones are inserted in the interleaved portion. Each data tone is modulated with respect to a nearest one of the inserted pilot tones. The PDU is transmitted over a power line.

The present disclosure relates to a signal transmission method, system, device, a storage medium and an electronic device. The method includes: determining data to be transmitted by a unit in air conditioning units; and transmitting, by the unit, the data to be transmitted to other units through a designated power line in multiphase power lines, wherein the designated power line is any power line in the multiphase power lines, and the designated power line is a power line shared by all units in the air conditioning units.

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.

The embodiments of the present disclosure disclose a channel switching processing method, device and system, storage medium, and an electronic device. The channel switching processing method includes: acquiring a signal noise on a first channel corresponding to a first power line, wherein a communication signal is transmitted on the first channel; comparing a magnitude of the signal noise to a predetermined threshold; and in switching the communication signal from the first channel to the second channel corresponding to a second power line according to a comparison result.

This disclosure discloses a communication implementation method and device for air conditioning units, a storage medium and a processor. The method includes: acquiring a channel state of a current power line carrier channel used between units in an air conditioning system; and determining whether to switch the channel between the units from the current power carrier channel to a next power carrier channel according to the channel state, wherein the next power carrier channel is any one of power carrier channels other than the current power carrier channel in the air conditioning system.

A double alternating frequency algorithm (DAFA) uses a high frequency carrier wave (>1 GHz) that lies above environmental noise and is capable of carrying large amounts of data, stacks a plurality of N frequency channels on the carrier wave (e.g., one channel for each transformer serviced by a substation) and changes the frequency of the carrier wave at each transformer to repeat the data for downstream and upstream propagation for providing broadband Internet over power lines. This approach will fulfill the promise of broadband Internet to the vast rural areas of the United States that do not have access to broadband Internet. Furthermore, this approach will provide another revenue source for utility companies to leverage the existing power distribution system.

A broadband over powerline (BPL) unit is provided. The BPL unit includes at least one processor programmed to execute a first virtual machine and a second virtual machine, at least one memory device in communication with the at least one processor, and a powerline transceiver. The at least one processor is programmed to transmit and receive data over a three-phase power line via the powerline transceiver. The at least one processor is also programmed to receive, via the first virtual machine, a first plurality of data for transmission via the powerline transceiver, receive, via the second virtual machine, a second plurality of data for transmission via the powerline transceiver, transmit, via the powerline transceiver, the first plurality of data via a first phase, and transmit, via the powerline transceiver, the second plurality of data via a second phase.

Aspects of the subject disclosure may include, for example, receiving, by each of a plurality of receivers, one of a plurality of electromagnetic waves, each electromagnetic wave of the plurality of electromagnetic waves guided by a different one of a plurality of twin-lead transmission lines, each twin-lead transmission line sharing a wire, and each electromagnetic wave of the plurality of electromagnetic waves including a different one of a plurality of communication signals, and obtaining, by each of the plurality of receivers, one of the plurality of communication signals. Other embodiments are disclosed.

Aspects of the subject disclosure may include, for example, a system for modulating a first electrical signal to generate first modulated electromagnetic waves, and transmitting the first modulated electromagnetic waves on a waveguide located in proximity to a transmission medium. In one embodiment, the first electromagnetic waves can induce second electromagnetic waves that propagate on an outer surface of the transmission medium. The second electromagnetic waves can have a first spectral range that is divided into, contains or otherwise includes a first control channel and a first plurality of bands. Other embodiments are disclosed.

Embodiments include methods of powerline communications using a preamble with band extension is provided. A method may include receiving a packet data unit PDU. Bit-level repetition is applied to at least a portion of the PDU to create a repeated portion. Interleaving is performed per a subchannel. Pilot tones are inserted in the interleaved portion. Each data tone is modulated with respect to a nearest one of the inserted pilot tones. The PDU is transmitted over a power line.