Patent ID: 7599624

Claim:
A channel switching system in a wavelength division multiplexing passive optical network (WDM-PON), the system comprising: a signal generator generating signals on N channels using N light sources, for N>than 1, each light source including a wavelength tunable laser, wherein the wavelength tunable laser is a distributed Bragg reflector laser diode (DBR-LD) or a sampled grating distributed Bragg reflector laser diode (SGDBR-LD); a channel tuner switching channels by changing the wavelengths of the lasers so that at least one of the N channels have the same wavelength; a time division multiplexing (TDM) unit time-multiplexing two or more channels of the at least one of the N channels having the same wavelength; and a tracer optimizing a signal of a signal detector by monitoring a relative magnitude change between the signals of the signal detector and wavelength optical signals of the light sources and properly changing wavelengths of the light sources and a temperature of a thermo-electric controller if the signal of the signal detector deteriorates.