Maneuver at Lightspeed: Electromagnetic Spectrum as a Domain

Reading Time: 10 Minutes

By: Robert “STAN” Smith

The mission of the US Air Force is to fly, fight, and win in air, space, and the electromagnetic spectrum (EMS). While it does not quite sound as smooth, the truth is that cyberspace is not a domain. In fact, focusing on cyberspace as a domain, or even as a set of effects, is a barrier to multi-domain operations. By limiting the scope of cyberspace to “a domain within the information environment,” planners unconsciously ignore the dilemmas that every other domain can use to hold computer networks at risk. By ignoring cyberspace’s reliance on the EMS, planners mischaracterize the fundamentals that are critical to basic electronic communication. Planners more effectively incorporate EMS capabilities by focusing on desired effects first, rather than the means of an effect. Leaders that understand the EMS can effectively describe maneuver characteristics within the spectrum, specify vulnerabilities and strengths, and build a comprehensive plan to establish EMS dominance. This article focuses on describing EMS maneuver in both free space and wired networks. Those who see maneuver in radio frequency (RF) energy rather than solely in cyberspace open their planning capabilities to multi-domain operations. Confining effects, nodes, or maneuver to “cyberspace” prevents planners from considering all potential vulnerabilities and capabilities. It all starts with the fundamental physics of the EMS.

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When you think of capabilities that use the EMS domain, what comes to mind first? Airmen may immediately pick aircraft radios as a widely-used tool. Other everyday interactions with the EMS include over-the-air television signals or the local news station’s weather radar. Missiles guided by infrared (IR) seekers, and the flares that defeat them, rely on the underlying physics that define the EMS. Directed energy weapons, such as high-powered microwave (HPM) or electromagnetic pulse (EMP) weapons, also function within the EMS. Even visible light represents a band of the EMS that you perceive with your eyes. It is easy to prove all these capabilities fall under the EMS because you can point to the band of the spectrum they exist in. Aircraft radios are generally very-high frequency (VHF – 30 to 300 megahertz (MHz)) or ultra-high frequency (UHF – 300 to 3,000MHz), while weather radars often operate in the S- or C-bands. Operating frequency is a fundamentally defining characteristic for any capability in the EMS and is a starting point for defining EMS maneuver later in this article. Electromagnetic waves, made of photons, typically transit free space. Electricity, on the other hand, transits wired networks as electrons. As an aside, fiber-optic cables enable photon-based wired networks. Both free space and wired networks rely on Maxwell’s equations describing electric and magnetic fields whether a computer is connected to the network or not. Cyberspace is simply one way to utilize both wired and free space networks.

Consider the device that you are using to read this article. If on a computer, you may be browsing the internet through Wi-Fi. Based on Institute of Electrical and Electronic Engineers (IEEE) 802.11 standards, Wi-Fi typically operates at 2,400MHz and 5,000MHz (among other ranges). If you are using a 4G LTE connection through your smartphone in North America, it may be residing in the 800MHz frequency range. The data your computer or smartphone is processing certainly exists in an “interdependent network of information technology (IT) infrastructures,” as Joint Publication 3-12 defines cyberspace. But that Wi-Fi or 4G cyberspace data is simply a vehicle traveling along a free space path in the EMS. This is an important distinction because the EMS path that your data travels along may be an exploitable vulnerability in another domain. Your cyberspace data has identifiable characteristics outside of the cyberspace network. Your cyberspace data is vulnerable to non-cyberspace effects.

One of the most important takeaways is to understand your network (or an adversary’s network) to identify critical nodes and capabilities. Military planners must determine how to protect (or disable) these nodes or capabilities to support mission objectives. It is critical to note that your network data has interdependencies across multiple domains (Space, Land, Maritime, etc.). As you browse the internet your data may begin through air transmissions on Wi-Fi to a router, transit through underground cables to land-based servers, may cross the Atlantic via submarine cable, or even rely on space-borne satellites if communicating with a SATCOM user. Each of these nodes or lines represent a potential vulnerability. Cutting a submarine cable, whether intentionally or by force of nature, is a maritime domain effect and not a cyberspace effect even though the result heavily impacts computer networks. Planners must account for multi-domain interdependencies required for operations in the EMS when faced with adversaries such as China, who seek to pair EW and network attack tools for a “more holistic and complete attack against an adversary’s command networks.” It is not the computer network that defines data transmission; it is the EMS.

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Operating frequency is a fundamental definition and is vital to understanding maneuver within the EMS. What is also vital is that the EMS propagates at the speed of light (in a vacuum). Essentially, the speed of maneuver in the EMS is at the speed of light. Gen Goldfein, USAF Chief of Staff, stated that multi-domain C2 “[links] operations moving at the speed of light with operations moving at the speed of sound.” Maneuver in the other domains varies greatly, but typically at a much slower speed than the EMS. An M1A2 Abrams main battle tank maneuvers through the Land domain at, or under, 40 mph. Aircraft, like the C-17 Globemaster, transit the Air domain at several hundred nautical miles an hour. It is easier to imagine maneuver through Land, Air, and Maritime domains because we can visibly see the vehicle travel. In the EMS, the wave or frequency is invisible, except for visible light itself. Even the transit of visible light is imperceptible to the human eye; a light is either on or off, we do not perceive the transition. Maneuver still matters to the EMS, though, even with a near-instantaneous speed. Rather than speed, maneuver within the EMS relies on access.

Access to the EMS begins with an equipment-based component or the functional method that enables a user to act within the EMS. First, consider a standard internet user; we will call him Ralph. Ralph sits in a city coffee shop with his laptop and smartphone. At this moment, Ralph is present on the EMS with laptop Wi-Fi (5,000MHz) and smartphone 4G (800MHz). While reading this article online using his laptop, Ralph notices the laptop battery is nearly empty. His response is to turn off the laptop and read the article from his smartphone instead. Ralph has maneuvered functionally from 5,000MHz to 800MHz, using different equipment for the same purpose. While battery life provides a good example, consider instead if Ralph was coerced to transition from laptop to smartphone by a Wi-Fi jammer. Jamming at 5,000MHz would not affect signal transmission at 800MHz as the two positions have significant separation. That Ralph’s data resides in cyberspace, is encrypted, or even if Ralph was the target in the first place does not matter. The Wi-Fi signal is denied or degraded due to its position, or frequency, in the EMS.

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Communication via aircraft radios represent another, more military-focused example of intentional maneuver in the EMS. Imagine Ralph now as a fighter pilot communicating over a single channel UHF radio, notionally 310MHz. In this example, the radio communication represents the desired access. While maneuvering in the Air domain in his aircraft, Ralph also exists in the EMS at 310MHz, where an EMS-savvy enemy may detect him. If that enemy were to maneuver significant EM interference to Ralph’s position in the EMS (simply, jam Ralph’s radio), Ralph’s response should be to maneuver to a new position, or frequency, in the EMS. Frequency-hopping radios take EMS maneuver to the next level, maneuvering automatically between thousands of channels and making a counter-maneuver much more difficult. Imagine trying to shoot a target that continuously appeared and disappeared in different locations! That would be a significant feat of maneuver in any other domain. While these various methods of maneuvering in the EMS are important, the system that brings the equipment to the fight is equally impactful. A more macro-level system component of EMS maneuver ensures that the equipment is within range of the intended target.

The system (aircraft, ship, tank, etc.) that delivers a specific EMS effect does so by entering the operational environment via another domain. A land-based electronic warfare (EW) team may employ EMS effects from antennas (free space) or through a wired connection. If employing free space, or atmospheric effects, line of sight limits this land-based team’s access. The line-of-sight limitation is mitigated to an extent by maritime, air, and space systems. Satellites, for instance, have a relatively large field of regard. Planners for the EMS must consider how their effects are gaining access to the environment. There is more detail to be found in free space path loss, atmospheric attenuation, skywave propagation, and other EM fundamentals, of course. For the purpose of this article, however, the domain supporting atmospheric EMS employment (air, land, maritime, etc.) has the greatest impact on range. A handheld VHF radio does not stand much chance of accessing a net a hundred miles away, for instance. But that same radio would have access if installed on an aircraft and flown closer to the desired net or at an altitude that would enable line-of-sight of that net. The concept seems obvious but applies to jammers, directed energy weapons, and any other EMS capability that exists. Most free space effects require relatively close proximity (tens to hundreds of miles), a vulnerability not always shared by wired network effects.

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The effective range of an EMS effect has a direct impact on the risk assumed by the delivery system. An Army EW team may need to be within a few miles of the forward line of own troops (FLOT) to access its target, increasing risk of attack. If the target can be accessed through a wired network, however, a cyber team can nearly instantaneously employ effects from safety, thousands of miles away from the battlefield. Planners should be asking if both means satisfy the desired effect and support mission objectives. If the objective is to exploit a specific link, and that exploitation can be accomplished from safety, the decision seems obvious. If the link is inaccessible or undiscovered through wired networks, the exact same effect may be possible through a free space effect in a theater. Note that the link’s composition does not necessarily matter in accomplishing the objective. Whether computer-based (cyberspace) or simply electronic, wired, or atmospheric, the planner cares about satisfying the desired effect.

Planning to cyberspace effects and cyberspace targets misses the bigger picture of how networks actually function. True multi-domain operations must consider how the EMS domain depends on capabilities in the land, maritime, space, air, and human domains to transmit effectively. Computer-based networks, or cyberspace, represents only a subset of EMS operations that can be influenced by the other domains. The EMS provides planners with greater flexibility in accomplishing objectives than if they focus solely on cyberspace effects. By leveraging strengths and accounting for weaknesses across multiple domains, our forces can present unanticipated dilemmas to an adversary. Our planners must understand linkages between the EMS and other domains to leverage all means available to attack enemy networks, achieve EMS superiority, and ultimately execute true multi-domain operations.

Maj Robert “STAN” Smith is a student in the Multi-Domain Operational Strategist program at the USAF Air Command and Staff College. He is an RC-135V/W RIVET JOINT Electronic Warfare Officer with multiple deployments to US Central Command and European Command. He can be found on Twitter as @RJStan_. 

The views expressed are those of the author and do not necessarily reflect the official policy or position of the Department of the Air Force or the U.S. Government.

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3 thoughts on “Maneuver at Lightspeed: Electromagnetic Spectrum as a Domain

  • November 5, 2018 at 10:36 am

    Major Smith – Great article. I’ve been involved in a lot of EMS Domain discussions, but I had never thought about the multi-domain angle to the extent that you have in this article.

    I think the warfighter needs to step up and drive this discussion more aggressively because they (more so than the Services) own the operational problem of EMS maneuver. In any case, we need more articles like this. Well done!

    • November 6, 2018 at 7:03 am

      Thank you! I agree, those who do hands-on work in the EMS need to jump in the conversation more often! The desired end result can get muddied with policy and


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