Ciena, Ericsson and Telstra recently announced they had successfully demonstrated 400 gigabit per second (Gbps) speeds over 61.5 GHz spectrum on Telstra’s transmission network in Melbourne. This demonstrates the highest spectral efficiency per fibre pair ever achieved in a live environment and enables up to 30.4 terabit per second (Tbps) bandwidth on Telstra’s transmission network in Melbourne. This demonstration achieves world’s highest transmission capacity over a single fiber pair. Previously, the highest capacity on record was 25.6 Tbps. And it also achieved 24 Tpbs transmission capacity over a single fiber pair using C+L dual-band technology on PLCN subsea cable network.