For decades, high-frequency (HF) radio was the workhorse of long-distance military communication — until satellites came along and largely displaced it. Now, according to IEEE Spectrum, that older technology is drawing renewed strategic interest from militaries and governments.
The reason, IEEE Spectrum reports, is a mix of new vulnerabilities and new capabilities. Satellites, once seen as the superior successor, have their own weak points, and defense planners are increasingly wary of relying on them alone. At the same time, HF itself has improved. The publication points to modern wideband waveforms and automatic link establishment — technology that helps radios find and maintain a usable channel on their own — as key drivers of the renewed investment.
HF works by bouncing signals off the upper atmosphere, allowing communication across very long distances without any orbiting infrastructure. That independence is part of its renewed appeal: a system that does not depend on satellites cannot be knocked out by threats to those satellites.
IEEE Spectrum frames the shift as an examination of why HF declined, what has changed, and how satellites overtook it in the first place. The through-line is that a communications method many had written off is being reconsidered as a resilient backup — or even a primary channel — in contested environments.
Why it matters: as militaries confront the risk that space-based communication could be jammed or destroyed, older, ground-independent technologies like HF are being re-evaluated as a hedge against losing contact when it matters most.