Meta’s Project Petal details the architecture of the first petabit-class transoceanic subsea cable system, spanning 7,000 km between France and the United States. Deploying space-division multiplexing (SDM) with multi-core fibers across 24 to 32 fiber pairs, it doubles capacity per fiber without proportional power escalation, surpassing 1 Pbps across Atlantic routes. engineering.fb.com