Evolving Optical Transport: 400G, Network Design, and Regional Diversity#

Abouzar Asadi (Chorus)

• Why: Coherent optics and line-system evolution are core to the PM's physical DC/WAN interconnect interests. A nationwide 400G rollout on NZ's largest open-access fibre network is one of the few talks here with real optical engineering content: line-system readiness, spectrum management, transceiver evolution, and ring diversity/protection.
• What: The engineering journey to 400 Gbps nationwide on Chorus's network — what had to be true about the optical line system before 400G could ride it, how spectrum is managed, and how regional fibre rings are designed for diversity and protection (from abstract only).
• How: Advances in coherent modulation and digital signal processing plus open optical architectures; diverse ring design and protection strategies for resiliency and service continuity.
• Where applicable: Chorus/NZ-specific deployment, but the engineering content (line-system readiness for higher baud, spectrum planning, ring protection) transfers directly to any long-haul or metro optical operator. Watch for whether the "open optical" framing stays vendor-neutral.