Software-defined radio in military communications · Wiki

A software-defined radio (SDR) is a radio in which functions that were once fixed in hardware, such as modulation and signal processing, are implemented as software running on programmable processors. In military communications the central idea is the waveform: the complete set of rules for how a signal is formed, protected and interpreted. If a waveform is software, the same terminal can load different waveforms, and a waveform can be ported to terminals from different manufacturers.

Why the approach was adopted

Conventional radios tie each capability to dedicated hardware, so interoperability depends on everyone buying the same equipment. Allied forces have long faced the opposite situation: many national radios that cannot exchange voice or data with one another. Moving the waveform into software offers a route to a common waveform implemented by several industries, with updates delivered as software instead of hardware replacement. This is one expression of the wider shift described under software-defined defence.

ESSOR as a public example

The European Secure Software defined Radio (ESSOR) programme is managed by OCCAR, the Organisation for Joint Armament Cooperation, for Finland, France, Germany, Italy, Spain and Poland. The European Commission describes its aim as giving Europe a military SDR capability and a common industrial base. In 2021 the Commission made a direct award of EUR 34.6 million to co-finance ESSOR activities under the European Defence Industrial Development Programme. Related EU funding for defence research and development now sits within the European Defence Fund.

An interoperability test on 24 March 2022 at laboratories in Poland used radios from four European manufacturers, based in Finland, France, Italy and Poland. The Commission reported that it showed forces from different member states could communicate using their own radios. The Commission added that further tests in 2023 would add a German radio to the five radios certified at that point.

Standardisation

Waveforms become useful to alliances once they are standardised. NATO published STANAG 5651 Edition 1 on 23 October 2023. It is titled HDRWF, a High Data Rate Waveform for UHF Radio, and the covered standard is the ESSOR high data rate waveform standard of 2023. It shows a waveform developed in a European programme moving into the NATO standardisation framework described under STANAG.

Why it matters for defence technology

SDR changes what is bought. Waveforms, the software architecture and the certification process become assets to be specified and controlled, alongside the physical terminal. It also affects industrial structure, because a common waveform lets several suppliers compete to build compatible terminals.

What to watch

Whether further ESSOR waveforms follow the high data rate waveform into NATO standards.
How software updates to fielded radios are certified and released.
The relationship between new waveforms and existing tactical data links.
The extent to which non-participating nations adopt the same waveforms.