This paper reports the world's first field trial of a 100-km reach symmetric-rate ten gigabit Ethernet passive optical network (10G-EPON) system that uses optical-amplifier-based PON repeaters. Semiconductor optical amplifiers (SOAs) are utilized to handle the 10G-EPON wavelength allocation defined in IEEE802.3av; a fast automatic level control technique is applied to cascaded SOAs for upstream amplification to achieve high gain and wide input dynamic range. An electronic dispersion compensation technique is also applied for downstream detection. These techniques support a 79.5-dB loss budget and 100-km reach transmission with 40 km span lengths. In a field trial, we successfully demonstrate bidirectional real-time uncompressed high-definition television signal transmission over installed standard single-mode fiber links.