Unrepeated HCF Transmission over spans up to 301.7 km

We transmit real-time data-signals over HCF span-lengths reaching 301.7 km using a novel high-power (37 dBm) HCF line-system, achieving full C-band system data-rate of $25.6 \mathrm{~Tb} / \mathrm{s}$ after 200.5 km with negligible fiber transmission penalty, demonstrating the potential of HCFs to expand unamplified links.