Patent ID: 7817920

Claim:
A method for providing a short-distance communication using visible light in a communication terminal in which multiple wavelengths of the visible light used for the short-distance communication are set up as transmission wavelengths, the method comprising: scanning ambient light; measuring an optical power of each of the ambient light having same wavelength as the transmission wavelengths; comparing a minimum transmission optical power of the respective transmission wavelengths with the measured optical power of the ambient light having wavelength corresponding to the transmission wavelength; if the measured optical power of all the ambient light is greater than the minimum transmission optical power, comparing a real transmission optical power of the respective transmission wavelengths with the measured optical power of the ambient light having wavelength corresponding to the transmission wavelength; if the measured optical power is less than the corresponding the real transmission optical power, detecting a difference between the measured optical power of the ambient light and the real transmission optical power; and performing the short-distance communication using the visible light having the transmission wavelength corresponding to the largest detected difference among the detected differences of optical power.