Patent ID: 6738578
Filing Date: 2004-05-18
Classification: H04B

Abstract:
An optical communication method used in a communication network in which communication is had between a control node and a number of controlled nodes using light rays amplitude-modulated by a carrier modulation signals of a first pre-set frequency range, comprising:a step of transmitting a transmission permission signal from the control node to each controlled node; and a step of starting or interrupting light emission of the light rays from a light emission circuit with desired transient characteristics by each controlled node having reference to said transmission permission signal, whereby the transmission permission signal (i) informs the respective controlled node as to when transmission of the light rays is to start or stop and (ii) enables the light emission circuit of a respective controlled node to be activated or deactivated, and wherein said desired transient characteristics are such that frequency components generated on starting or interrupting the emission of the light rays by said controlled node are not generated in a frequency range of approximately 33 kHz to 6 MHz.