A method, a system, and a non-transitory computer-readable memory resource containing instructions for transmitting data are provided. In an example, the method includes providing a header signal having a first optical property. The header signal indicates a start of a packet, and has a minimum period between transitions that is less than a frame period of a receiving device and greater than a scanline period of the receiving device. A payload signal of the packet is provided that has a second optical property that is different from the first optical property. The payload signal has a minimum period between transitions that is less than the frame period of the receiving device and greater than the scanline period of the receiving device.

The invention relates to a bidirectional wireless communication device which is based on the use of light, including emitting modules, each emitting amplitude- and/or phase-modulated light; and a receiving module made up of: a photodetector illuminated by said modulated light and generating a modulated electrical signal in response to said modulated light; and a processing module for processing the signal generated by said photodetector. The receiving module includes an electronic means positioned between the photodetector and the signal-processing module and capable of matching the impedance of the photodetector to maximise the signal-to-noise ratio of the electrical signal by minimising distortions of said electronic signal associated with incorrect impedance matching at the output of the photodetector, while maximising the level of the modulated electrical signal and the throughput of transmitted data.

Methods, systems, and computer readable media can be operable to facilitate recognizing and providing notification of events, states, and/or conditions associated with the CPE (customer premise equipment) device and/or associated networks or devices. An application running on a mobile device (e.g., smart phone) can be used to observe and diagnose electronic equipment (e.g., CPE device). Equipment can have indicators (audio, visual, etc.) that a human would have difficulty interpreting correctly. A mobile device application can be programmed to observe audio and/or visual indicators, report status and possibly recommend course(s) of corrective action to the user. Since the information observed by the mobile device is unidirectional (from the equipment to the mobile device) there is no increased security risk.

A system with which any abnormality can easily be 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; and a second modulator that acquires a 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 first modulator generates, as an extinguishing signal, the control signal for extinguishing the first light source by an extinguishing period. After a lapse of the extinguishing period, the first modulator generates, as a light ID signal, the control signal for transmitting a visible light signal by luminance variations of the first light source.

The system includes an active unit, such as a detector unit, which has a processor, a network port for connection to a central control unit, and an optical data input port. The processor is arranged to enable the optical data input port on receipt of an enable signal received by the active unit from the central control unit via a network.

A LiFi system having multiple transceivers (11) and a single multiple-input- multiple-output (MIMO) modem (41) with at least M outputs, wherein the M transmit outputs of the MIMO modem (41) are fed to a linear combiner (42). The linear combiner creates M distinct linear combinations based on the N MIMO transmit branch signals of the MIMO modem and the linear combinations are chosen such that they allow decoding of each of the5 N MIMO transmit branch signals when N of the M distinct output signals are received.

This invention relates to an interference handling method and system for an optical wireless communication system, wherein multiple levels and operating modes are provided to flexibly handle partitioning of a coordination functionality between a central entity and distributed entities. Thereby, the coordination functionality which relies on interference reports from devices in overlapping coverage areas of access points can be central or distributed over access points or partly central and partly distributed.

An electronic apparatus is disclosed. The electronic apparatus includes: a communication interface comprising communication circuitry and a processor configured to: control the communication interface to transmit a signal of a first carrier frequency, and based on a signal generated as the signal of the first carrier frequency reflected by a space where the electronic apparatus is disposed not being received through the communication interface within a first threshold time after the signal of the first carrier frequency is transmitted, determine the first carrier frequency as a search carrier frequency; based on the reflected signal being received through the communication interface within the first threshold time after the signal of the first carrier frequency is transmitted, control the communication interface to transmit a signal of a second carrier frequency different from the first carrier frequency; control the communication interface to transmit a signal of the determined search carrier frequency; and identify whether an object is present based on whether a signal is received through the communication interface within a second threshold time after the signal of the search carrier frequency is transmitted.

Embodiments relate to a local free space optical (FSO) terminal that transmits and receives optical beams. The FSO terminal includes a fore optic and a dispersive optical component. A receive (Rx) optical beam from a remote FSO terminal is received and focused by the fore optic to a Rx spot at a focal plane of the fore optic. A transmit (Tx) optical beam with a different wavelength forms a Tx spot at the focal plane and is collimated and projected by the fore optic to the remote FSO terminal. The dispersive optical component is positioned along optical paths of both the Rx beam and the Tx beam. Among other advantages, a wavelength dependence of the dispersive optical component laterally separates the Rx spot and the Tx spot at the focal plane.

A load control device for controlling the power delivered from an AC power source to an electrical load is able to receive radio-frequency (RF) signals from a Wi-Fi-enabled device, such as a smart phone, via a wireless local area network. The load control device comprises a controllably conductive device adapted to be coupled in series between the source and the load, a controller for rendering the controllably conductive device conductive and non-conductive, and a Wi-Fi module operable to receive the RF signals directly from the wireless network. The controller controls the controllably conductive device to adjust the power delivered to the load in response to the wireless signals received from the wireless network. The load control device may further comprise an optical module operable to receive an optical signal, such that the controller may obtain an IP address from the received optical signal and control the power delivered to the load in response to a wireless signal received from the wireless network that includes the IP address.