(Radio) The upstream (ascending) wavelength of the 10G EPON system is:

According to IEEE 802.3av wavelength planning adopted by Huawei 10G-EPON, downstream uses 1577 nm and 10G upstream uses 1270 nm. In asymmetric coexistence, 1G-EPON upstream uses 1310 nm, but for 10G-EPON upstream specifically the wavelength is 1270 nm. Therefore the correct upstream wavelength for 10G-EPON is 1270 nm.