Delay is Not an Option

TLDR

SpaceX has filed plans with the FCC to build a constellation of 4,425 low‑Earth‑orbit satellites. The study builds a simulator from FCC filings to evaluate laser link usage, routing, and low‑latency performance of the proposed satellite network. The network employs phased‑array antennas for uplink/downlink and inter‑satellite laser links, and the authors simulate this architecture to assess routing and latency. The simulation shows that the satellite network can deliver lower latency than terrestrial optical fiber for distances over ~3,000 km, demonstrating superior low‑latency performance.

Abstract

SpaceX has filed plans with the US Federal Communications Committee (FCC) to build a constellation of 4,425 low Earth orbit communication satellites. It will use phased array antennas for up and downlinks and laser communication between satellites to provide global low-latency high bandwidth coverage. To understand the latency propertes of such a network, we built a simulator based on public details from the FCC filings. We evaluate how to use the laser links to provide a network, and look at the problem of routing on this network. We provide a preliminary evaluation of how well such a network can provide low-latency communications, and examine its multipath properties. We conclude that a network built in this manner can provide lower latency communications than any possible terrestrial optical fiber network for communications over distances greater than about 3000 km.