> dedicated sub-oceanic lines (Hibernian Express is a major provider), even microwave networks.

This statement as a definitive "this is how it works" makes me think the person who wrote this doesn't really work in anything at the intersection of networking and HFT.

Much of the serious HFT for transoceanic stuff at low bitrates, but very important signalling messages, moved to shortwave radio with giant-ass aimed yagi-uda antennas several years ago.

You can go out to some places not very far from the CME datacenter in Illinois and find big, suspicious shortwave band things aimed at Tokyo.