PROTECTION SWITCHING ARCHITECTURE OF PASSIVE OPTICAL NETWORK BASED ON DENSE WAVELENGTH DIVISION MULTIPLEXING

摘要

A protection switching method in a DWDM-PON(Dense Wavelength Division Multiplexing Passive Optical Network) is provided to prevent service interruption due to a fault generated from a wavelength conversion unit of an OLT(Optical Line Terminal) and to adopt a 1:N protection switching scheme which is economical as compared to a 1+1 protection switching scheme. An OLT(400) in a DWDM-PON comprises a plurality of wavelength conversion units(401), a variable-wavelength conversion unit(404), an electric switch, an optical multiplexer(402), and a 2x1 optical coupler(403). The wavelength conversion units respectively convert inputted signals into optical signals having different wavelengths. The variable-wavelength conversion unit converts an inputted signal into an arbitrary wavelength through a tunable laser. The electric switch switches each signal, received from the external, as the input of an associated wavelength conversion unit or the variable-wavelength conversion unit. The optical multiplexer multiplexes the output of the wavelength conversion units. The 2x1 optical coupler adds the output of the optical multiplexer to the output of the variable-wavelength conversion unit. In case a fault occurs at an arbitrary wavelength conversion unit, the electric switch switches a signal, transmitted to the fault wavelength conversion unit, to the variable-wavelength conversion unit. In this case, the variable-wavelength conversion unit converts the signal into an optical signal having the wavelength of the fault wavelength conversion unit and transmits it to the 2x1 optical coupler.