Wavelength division multiplexing passive optical network (WDM-PON) is a fiber-to-the-home (FTTH) solution characterized by the use of a PON structure plus the use of multiple wavelengths that can be dedicated for each user or shared among a group of users. This increases the capacity of WDM-PON systems beyond those where a single wavelength is shared among all users. WDM-PON is being standardized by the International Telecommunication Union, supported by the Next-Generation Access initiative from the Full Service Access Network (FSAN).