Transmission Timing on Optical Data-Center RotorNet for Reduced Cost, Energy and Latency

RotorNet comprises switches that provide direct all-to-all connectivity among data-center nodes by cycling among all cyclic shift permutations. Combined with two-hop routing, whereby packets traverse the optical network twice, they provide high throughput regardless of the traffic pattern and with no need for centralized control. Although being a circuit-switched optical interconnect intended primarily for latency-insensitive traffic, reducing latency saves energy and buffer space, and is thus important. We show that latency can be reduced by properly timing the transmissions by the sender, and offer insights along with some useful results.