Abstract: A method for providing a user interface based on a light sensor includes recognizing a motion of an object with respect to a portable device based on a light signal received by at least one light sensor of the portable device and, according to the motion of the object, controlling an application of the portable device. A portable device to provide a user interface based on a light sensor includes at least one light sensor to recognize a motion of an object with respect to the portable device based on a light signal received by at least one light sensor and a control unit to control an application of the portable device according to the motion of the object.

Abstract: A transmitting apparatus includes a controller to classify data to be transmitted and to select a corresponding wavelength, a signal modulator to encode the data into an electrical signal, and a light emitting unit to emit a visual light at the selected wavelength based on the electrical signal. A receiving apparatus includes a controller to classify data to be received, and to select a corresponding wavelength, an optical filter to receive and filter a visible light, a visible light receiver to transform the filtered visible light into an electrical signal, and a signal demodulator to demodulate the electrical signal into digital data. A transmission method includes classifying transmission data, selecting corresponding wavelength, and encoding the data into an electrical signal to transmit. A receiving method includes filtering a received light, transforming the filtered light into an electrical signal, and demodulating the transformed electrical signal into digital data.