Overseas Telephony before the Undersea Cables

Prior to the laying of the first transatlantic telephone cable in 1956, all overseas calls were made via high frequency radio links, which remained in service until cable and satellite links provided global coverage and adequate capacity.

A post here on 2022-04-03, “Transatlantic Radiotelephone Reception in the 1940s”, described how reliable telephone service was achieved using famously flaky radio channels.