A.0.4~0.5dB/km B.0.3~0.4dB/km C.0.2~0.3dB/km D.0.5~0.6dB/km
A.1~1.2dB/km B.0.6~0.8dB/km C.0.8~1dB/km D.0.4~0.6dB/km