Transmission of 40Gbit/s NRZ signal was successfully demonstrated over 219km of installed SMF in KT’s Daejeon area network. After transmission, the measured power penalty was 0.5dB for all the tributary channels. Transmission of 40 Gbit / s NRZ signal was successfully demonstrated over 219 km of installed SMF in KT’s Daejeon area network. After transmission, the measured power penalty was 0.5 dB for all the tributary channels.