Time and Wavelenght Division Multiplexed Passive Optical Network (TWDM-PON) is the next-generation fiber access (FTTx) technology, providing an upgrade path for the current Gigabit Passive Optical Network (GPON) for ultra-broadband services. TWDM-PON enables transmission on four or more wavelengths per fiber, each of which being capable of delivering symmetrical or asymmetrical bit rates of 2.5 Gbps or 10 Gbps.