Hudson Institute Fellow Bryan Clark has told the Senate Commerce Committee that it’s better to hoard mid-band spectrum for (vague and poorly-specified) future military purposes than to auction it for civilian use. That’s his testimony in tomorrow’s hearing, “America Offline? How Spectrum Auction Delays Give China the Edge and Cost Us Jobs.”

His reasoning (see full testimony on Committee website day of hearing) is a bit convoluted. While he admits that China has allocated more mid-band for mobile and fixed wireless than the US, he claims that such assignments are illusory because our rival allows its military (the People’s Liberation Army or PLA) to pre-empt civilian access if and when it needs the spectrum for warfare.

Discounting innovation effects that have historically reduced spectrum footprints, Clark insists that the military needs for spectrum in the US will only grow: “The US military will require more, not less, access to the electromagnetic spectrum in the coming decade.” Along with these claims, he urges a path to “co-existence” between civilian and military systems through undefined “sharing schemes.”

Relearning Basic Lessons

He admits that such sharing schemes do not currently exist and cautions that they are likely to be very complex, reducing the commercial value of shared spectrum: “The time and investment needed to implement these approaches will reduce the value of spectrum at auction. This cost and complexity will only grow as the DoD’s need for spectrum increases as a result of new operational concepts and missions.”

Clark implies that military needs should be satisfied by dedicating new spectrum bands to the military for exclusive use first, only opening them to civilian use after sharing schemes are created. In fact, Clark’s approach guarantees that the “Iron Dome” missile defense system desired by the administration will be a sitting duck for disruption by adversaries.

Dedicating bands for exclusive military use makes them easily identifiable to adversaries bent on jamming, disrupting, and hijacking them for their own purposes. We’ve known this since Hedy Lamarr created a frequency hopping system to fire torpedoes, but it seems that every generation of military spectrum aficionados has to learn it anew.

Protection by Stealth

The only practical way to protect military wireless data streams from jamming is to hide them inside and alongside frequency bands commonly used for other purposes, including civil bands and those used by the adversary’s own systems. Declaring 4, 7, and 8 GHz military bands simply ensures they will be first attacked in the event of war.

You don’t build resilient and reliable military systems on the back of regulation; you need to rely primarily on engineering and innovation. If these skills are scarce in the military-industrial complex, we need to expand its membership.

China’s pre-emption approach to civilian spectrum is vulnerable as well, because warfighters can easily tell (from traffic signatures among other features) when a band has been converted to military use. The ideal approach, as we’ve learned from Russia’s invasion of Ukraine, is to layer military data streams inside civilian Wi-Fi, 5G, and LEO traffic.

Pulsed ultra-wideband is almost as good because it appears to the casual observer to be white noise. There are other ways to hide the prize from the enemy as well, including some that haven’t yet been discovered.

The Under-Utilized Asset

The Iron Dome system promoted by the Administration seeks to supplement existing missile defense with a Starlink-like constellation of satellite-borne sensors and increased use of military radar in the S and X bands within the borders. It is touted as offering defense against hypersonic missiles despite the absence of such missiles in the US arsenal, let alone hypersonic anti-missile missiles.

The plan is obviously incomplete, and it fails to consider the practicalities of using radar bands for data transfer itself. What better way to hide a data stream than to piggyback it on a conventional-looking radar signal?

We know that 5G signals can be used for motion detection, just as Wi-Fi signals can see what’s happening in the next room. Hence, it stands to reason the inverse of using stray energy for sensing is likely practical. This would be an additional use of spectrum already allocated to the military.

Changing the Calculus

Historically, the military has always placed the burden of spectrum sharing on the civilian sector. When primary users are free to design systems as they see fit, sharing can become too burdensome to even consider, as Clark emphasizes in his testimony.

I think we can make great progress in the development of military radio systems if we flip this practice on its head. If we require coordination – not just co-existence – between civil and military systems from the outset, we can land on best practices much more quickly. Tasking military system designers with active coordination before allocating spectrum rights to them, changes the whole ball game.

Active coordination is woefully lacking in the American system of spectrum rights. Our most widely used wireless data network, Wi-Fi, has only recently begun to consider it at all. Yet coordination between my Wi-Fi access point and those of my neighbors can do more to reduce interference than any addition to the Wi-Fi portfolio since OFDM over MIMO in Wi-Fi 4.

Active Coordination is Needed

Many network systems employ request-grant systems of coordination. This is found in DOCSIS cable modem systems to communicate needs for upstream bandwidth from cable modems to schedulers.

Wi-Fi Quality of Service (802.11e) stations communicate queue depth information to access point schedulers, and Wi-Fi 7 uses “colors” to communicate band preferences between access points.

The Wi-Media Ultra-Wideband systems shares bandwidth requirements across groups of stations in a distributed fashion to meet the greatest possible variety of simultaneous needs. In other words, we have the basic concepts down pat. We simply need to continue upgrading active coordination across the civilian/military boundary to build systems that are resilient, efficient, and resistant to jamming.

Continuing to demand static spectrum allocations in the presence of a dynamic threat environment simply will not take use where we need to go.