R&D and first commercial service of WDM-PON

We address the WDM-PON technologies that have been under research and development in Korea for recent years. Presented are the three schemes of Gigabit WDM-PON, all of which are technologically mature to a commercial level. Some of good features in WDM-PON are discussed, in terms of utilization efficiency of fiber infrastructure, transmission distance, convenience of system operation, and cost effectiveness.