Hiding in Plain Sight: Blending Comms into the Background
Camouflaging Signals in a Transparent Battlefield
Years ago, before the US military became overly focused on counterinsurgency operations and overly reliant on forward operating bases (FOBs) and large, loud, mine-resistant armor-protected vehicles (MRAPs), the military focused certain fundamentals.
Two of those fundamentals included the practice of camouflage and communications discipline.
As a young cadet and officer, I was instructed that “camouflage is continuous,” which meant that the camouflage applied to an individual, vehicle, command post or anything else, had to match the background. As a platoon leader on my second deployment, I felt ridiculous wearing a universal combat patterned uniform, a desert combat pattern vest and helmet, and forest patterned equipment. My camouflage wasn’t continuous and so I stuck out like a sore thumb.
On that deployment, I also noticed that we had abandoned the radio discipline once ingrained. We stopped using frequency hopping (FH) technology, shifting to single channel - cypher text (SC-CT). We moved to a less secure communications protocol for several reasons: first and foremost, it was to increase the ability for coordination and interoperability with our NATO allies and other partners that were part of the coalition (including the Afghan Army themselves). We felt comfortable doing that, as we weren’t facing a near-peer enemy.
Today, as we face an increasingly heated competitive space, we must return to the fundamentals, updating them with the newest technologies. We must seize the opportunity to apply the principle that “camouflage is continuous” to further secure our communications under a concept known as blending.
The Challenge of Secure Comms
As militaries have grown increasingly capable, they’ve grown increasingly reliant on technology to synchronize distributed operations in time and space. In military technologies, there’s always a cat-and-mouse game. One side innovates, and the other is close behind with a counter.
For example, in the Second World War, the Germans built Enigma to cryptographically secure their communications. The Polish responded by creating Enigma Doubles to crack the secure cables.
To further complicate the challenge of secure communications on the modern battlefield, we’ve seen a proliferation of sensors across the electromagnetic spectrum—creating what is known as a Transparent Battlefield. This means that we should assume that any transmission, any movement, anything that we do is observable by our adversaries.
And, our adversaries have more electronic warfare capabilities than we have. So, we must further assume that once they observe our transmissions, they can quickly target and either attack with kinetic or electronic measures. We’re seeing this reality play out in Ukraine as Russia and Ukraine contest communications, GPS transmissions, and more.
Background Noise
The good news is that there is a lot of background noise on the battlefield. As humans have developed technology, we’ve proliferated it all over the world, and there are likely very few places on the surface of the earth that don’t have electromagnetic radiation bouncing around at some frequency.
In other words, there are radio signals, TV broadcast signals, satellite transmission signals, X-rays, and other signals bouncing around even at the front of a battle, where an adversary may be trying to jam commonly used frequencies.
More importantly, an organization can easily map the spectrum in use in a specific area. Radio-frequency heatmaps provide the density of specific bandwidths in use. These heatmaps can be depicted in several ways, including a waterfall (depicting the relative strength at the site of measurement of multiple frequencies) or as signal coverage map (depicting the relative strength of a single frequency across a broader area).
The short of it is, that anywhere we go there are various emissions bouncing around.
Blending Techniques to Mask Comms
In the intro, I mentioned frequency hopping technologies. In frequency hopping, receivers and transmitters cycle through several frequencies, making precisely timed jumps coordinated by GPS. Imagine taking a song, and moving every other second of the song to a different radio channel. If you wanted to listen to that song, you’d have to constantly know which channel was coming next and time switching the channel perfectly. Frequency hopping technology is like that, except it happens at fractions of a second
Blending takes this idea one step further. It studies the background radiation and identifies commonly used frequencies. For example, maybe it has identified in a city the most popularly used bandwidths include 900 MHz, 1800 MHz, (commonly used bandwidths for cellphones), 2.4 GHz (used for WiFi), and a series of radio stations at 92.7, 95.1, 101.3, and 103.7 MHz. A military could specifically create a frequency hopping protocol that uses these specific frequencies, in an attempt to hide in the background.
Now let’s imagine that an enemy has destroyed all of the cellphone towers in a 20 mile radius as well as the radio tower broadcasting at 101.3 MHz. Properly blending communications would require the military then to drop those frequencies from its protocol, although they could add the next most commonly used ones in the area. Maybe, the military is operating in a European smart city, enabled by a low power, wide area network operating at 868 MHz, so it adopts this as one of its frequencies in its protocol.
Remember that adage ‘Camouflage is Continuous’? We’re applying it to communications through blending. Continuously updating the frequencies used to ensure that they are continuously replicating background radiation, makes communications harder to detect.
Challenges
Of course, adopting blending protocols will come with their own significant challenges.
As Winston Churchill once reminded us, “the only thing worse than fighting with allies is fighting without them.” Future military operations will most certainly involve the integration of partner forces, meaning that the interoperability requirements that forced the US military to abandon frequency hoping in Iraq and Afghanistan persists.
The only thing worse than fighting with allies is fighting without them.
Frequency hopping technologies also rely heavily on precision navigation and timing (PNT) technology, specifically GPS, to ensure that all receivers and transmitters are hopping to the same frequencies at the same time. Otherwise, only a garbled mess comes through the radio. Our PNT technologies are increasingly at risk. We’ve seen electronic jamming prevent the return of drones in Syria and we’ve seen the increasingly weaponization of space by China and Russia—including the launching of anti-satellite weapons. Numerous entities, including the military, are working to advance our PNT capabilities and break the reliance on space-based satellites. Nevertheless, that reliance persists, at least for now.
Finally, war is a horrible and destructive thing. As armies fight back and forth over territory, the destruction of more and more infrastructure supporting the background electromagnetic radiation is highly likely. This means a smaller and smaller pool of available frequencies to support military blended communications. Radio discipline (minimizing the number and duration of radio messages) becomes critical.
Despite these and other challenges, blending offers an attractive opportunity for exploring ways of improving military communications while protecting our forces.
Conclusion
Through numerous combat tours and attendance at patrolling schools and other professional development opportunities, I came to understand that my radio was far more important than even my rifle.
The military focuses heavily on the basics of “shoot, move, and communicate.” As our adversaries increasingly challenge traditional communications technology, blending our transmissions into the background noise offers an attractive opportunity to provide a layer of security, allowing us to hide in plain sight, and hopefully increasing the likelihood of mission success.
Keep building,
Andrew
US military is indeed trying to rid itself of its dependence on satellites in some areas… however it is at the same time embracing and doubling down on satcom, especially when it comes to the less resilient LEO starlink constellation. Unfortunately, a lot of the awesome capabilities offered by these satellites could be degraded or worse completely gone on day 1 of a conflict with a capable adversary. The DoD needs to treat this as the true existential threat it is, and invest heavily in securing it’s networks.