Huawei announced a prototype TWDM-PON system based on stacked XG-PONs with 4 or 8 wavelengths. The design required developing a new colorless ONU transceiver module, integrated transceiver module at the OLT, and a multi-wavelength management and control protocol. The system is a successor to a 40G TWDM-PON prototype previously announced.
Huawei said the chief advantages of TWDM is that it allows operators to scale capacity while reusing the existing ODN.
http://pr.huawei.com/en/news/hw-326491-twdmpon.htm#.UwLvhvmWWSo
