Network Optimization for Unified Packet and Circuit Switched Networks

Optimization and Engineering, 21(1):159-180, 2020.

• Final version

Internet traffic continues to grow unabatedly at a rapid rate, driven largely by more and more video content, from 1080p HD to 4K Ultra HD video streaming today, to 8K Ultra HD video streaming in the near future. Although the packet-switching approach used in Internet backbone networks has thus far been able to keep up, it is unclear whether electronic routers that have been used at the core of backbone networks will continue to scale to match future traffic growth. On the other hand, optical fiber and switching elements have demonstrated an abundance of capacity that appears to be unmatched by electronic routers. The rate of increase in optical transport capacity has been keeping pace with traffic growth. Thus, one way of keeping pace with future traffic demands is to build an all-optical backbone network. However, packet switching requires the buffering of packets, of which optical switches are not capable today, and it appears unlikely that reasonable size packet buffers can ever be practically realized in optics. On the other hand, circuit switching has a much simpler data transport, making it well-suited to optics and its vast capacity potential.