Jamming and Spoofing: Awareness, Warning Signs, and What to Do

Independence notice: RunBoard is an independent operations platform and is not affiliated with, endorsed by, or sponsored by any company, product, network, or agency named in this article. Names are used only for identification and education.

Two different failures: denying versus deceiving

It helps to separate two ideas that often get blurred together. Both involve a signal you depend on being disrupted, but they fail you in opposite ways.

Jamming is the denial of a signal. Conceptually, a receiver that expects to hear a clean transmission is instead overwhelmed, and the useful information gets buried. The effect on the user is loss: a channel goes quiet or turns to noise, a position fix stops updating, a device that normally locks on cannot. You lose access to something you had.

Spoofing is the deception of a receiver. Rather than blocking the signal, spoofing feeds the receiver a false but plausible one, so the device believes something that is not true. The danger here is more subtle than loss, because the equipment does not report a failure. It reports a confident answer that happens to be wrong: a location that looks valid but is not, a time that reads normal but has drifted, a lock that seems solid on a source that is not real.

The practical distinction for you is this. Jamming tends to announce itself as an outage. Spoofing tends to hide inside a normal-looking display. That is why spoofing is the harder of the two to catch and the one that most rewards a habit of cross-checking what your instruments tell you.

Why this matters to public safety

Public safety runs on two invisible dependencies. The first is voice and data radio, the way people on an incident stay connected to one another and to dispatch. The second is satellite navigation, the family of systems commonly grouped under GPS or the broader term GNSS, which quietly provides not only location but also the precise timing that many modern systems lean on.

When either dependency degrades, it rarely does so at a convenient moment. The scenarios that stress communications the most, such as large incidents, mutual aid responses, severe weather, and dense urban events, are exactly the moments when losing a channel or a position fix does the most harm. A crew that cannot reach command, an apparatus routing engine that shows the wrong street, or an automatic vehicle location map that places units where they are not, all create risk that compounds quickly.

The point is not to make anyone anxious about a rare event. The point is that the cost of these failures is high enough that recognizing them early and having a fallback is worth a small amount of preparation. Awareness is cheap. Confusion in the middle of an incident is expensive.

Warning signs worth noticing

You do not need to understand how interference is produced in order to notice its effects. The symptoms show up on ordinary equipment. Train your people to flag the following patterns, especially when several appear together or across multiple users in the same place at the same time.

• A channel drops for everyone at once. One radio failing is a radio problem. Multiple radios losing the same channel in the same area simultaneously is a pattern worth noticing.
• Unusual noise or a raised noise floor. Persistent hiss, buzzing, or a hash that makes a normally clear channel unusable, particularly if it appears suddenly and covers a specific area.
• A receiver shows a strong signal but no usable traffic. Some radios display signal strength. A strong reading with nothing intelligible coming through is the kind of contradiction worth logging.
• Multiple devices failing in one geographic pocket. If problems cluster tightly in space and clear up when units move away, the location itself is telling you something.
• Navigation positions that drift or jump. A location fix that slowly wanders off, snaps to an impossible spot, or shows units clustered somewhere none of them are.
• Timing errors on systems that depend on satellite time. Clocks or timestamped systems that suddenly disagree, or logs that show time behaving oddly, can be a downstream symptom.
• Symptoms that follow the map, not the equipment. The single most useful tell across all of these is geography. Problems tied to a place rather than to a device deserve a closer look.

The same symptoms have ordinary causes

Here is the honest and important caveat. Every warning sign above has mundane explanations that are far more common than deliberate interference. Jumping to the conclusion that you are being targeted is a mistake, and a costly one, because it can send you chasing a phantom while a simple fix sits in front of you.

• Terrain and buildings create dead spots, reflections, and coverage holes that mimic denial of a signal.
• System congestion on a busy incident can make a channel feel unusable without any outside cause.
• Equipment faults such as a failing antenna, a low battery, a loose connector, or a misprogrammed radio produce exactly these symptoms.
• Ordinary electrical noise from nearby machinery, chargers, and industrial sites can raise the noise floor in a specific spot.
• Atmospheric and space weather can degrade satellite navigation broadly and temporarily.
• Software and infrastructure outages upstream of you can take down navigation or data services with no local cause at all.

The right posture is not paranoia and it is not dismissal. It is disciplined curiosity. Notice the pattern, rule out the ordinary causes first, and keep intentional interference on the list of possibilities rather than treating it as the default explanation or refusing to consider it. Most of the time the answer is a bad connector or a coverage hole. Occasionally it is not. A good process handles both.

A cautionary example from navigation

The reason satellite navigation deserves specific attention is that the wider world has already seen what its disruption looks like at scale. In recent years the aviation sector has reported documented navigation problems in regions near certain conflict zones, where crews and systems have encountered both denial and deception of satellite navigation signals. Aircraft flight management systems, which lean heavily on precise position and time, have shown symptoms such as unreliable position information and false readings that had to be recognized and worked around by falling back to other means of navigation.

Two lessons carry over directly to public safety, and neither requires any interest in the geopolitics involved.

First, satellite navigation is not guaranteed. It is an extraordinarily useful utility that is nonetheless a radio signal arriving faintly from space, and it can be degraded. Any operation that has quietly become dependent on it, for routing, for mapping unit locations, or for timing, has taken on a dependency that can fail.

Second, and more instructive, the aviation response is the model to imitate. Crews did not treat the display as gospel. They recognized the symptoms, cross-checked against independent information, and reverted to methods that did not rely on the compromised signal. That habit of not trusting a single source blindly, and of having a trained fallback ready, is exactly the resilience worth building into your own operations. The takeaway is not that the sky is falling. It is that the people most dependent on this signal have learned to keep a backup and to question a fix that does not make sense.

What to do if you suspect it

Suppose the pattern is there: a channel is unusable across several units in one pocket, or a navigation display is behaving in a way that cannot be right, and the ordinary causes do not seem to fit. Here is a calm, defensive sequence. Notice that not one step involves understanding, reproducing, or countering the interference itself. Every step is about protecting the mission and preserving the record.

1. Recognize and slow down. Name what you are seeing out loud. Getting people to say "our navigation may be unreliable here" is half the battle, because it shifts the crew from trusting the instrument to verifying it.
2. Do not assume the worst or dismiss it. Hold the possibility of intentional interference alongside the ordinary explanations. Keep working the problem rather than deciding the answer prematurely.
3. Fall back to alternate communications. Move to a backup channel, an alternate talkgroup, a different band or system, cellular or landline where appropriate, or established runner and relay procedures. This is why redundancy is planned in advance rather than invented under pressure.
4. Fall back to non-navigation methods. Use known addresses, physical maps, local knowledge, and direct reporting of unit locations rather than trusting an automatic position that may be false. Confirm locations by voice.
5. Document as you go. Record the time, the exact location, which devices were affected, the specific symptoms, how long it lasted, and whether it cleared when units moved. Contemporaneous notes are far more valuable than a reconstruction written hours later.
6. Preserve records. Do not overwrite or discard logs, screenshots, or device data that might document what happened. If your systems keep automatic logs, make sure they are retained.
7. Escalate through your chain. Notify your communications leadership and command so the operational picture reflects a possible signal problem, and so the decision to report externally is made deliberately.

The entire goal of this sequence is to keep the incident running safely while gathering enough of a factual record that someone with the proper authority can assess it afterward. Your job in the moment is to adapt and document, not to diagnose the cause.

Reporting suspected intentional interference

A point of law that every communications officer should know: in the United States, intentionally jamming, blocking, or interfering with licensed radio communications is illegal. It is prohibited under federal law and enforced by the Federal Communications Commission, the FCC. This is not a gray area. Deliberate interference with licensed radio, and with public safety communications in particular, is a serious violation.

That legal reality is exactly why the right response to a strong, well-documented suspicion is to report it through proper channels rather than to investigate or respond on your own.

• Report suspected intentional interference to the appropriate authorities, including the FCC. The FCC handles harmful interference to licensed radio services. Your agency should know in advance how it will make such a report.
• Bring documentation. The records you preserved, times, locations, affected devices, symptoms, and duration, are what make a report actionable.
• Coordinate through your own leadership and radio system operator. Your system administrator, regional interoperability coordinator, or radio vendor support may need to be involved, and some reporting is best routed through them.
• Involve law enforcement partners where a crime may be in progress affecting safety of life, following your agency's own protocols.

Decide the reporting path now, while it is a calm planning exercise, so no one has to figure it out during an event.

Building resilience so one signal is never everything

The strongest defense against both denial and deception is not detection. It is designing operations so that no single signal is a single point of failure. If losing one channel or one navigation source degrades you gracefully instead of stopping you, then interference, whatever its source, becomes an inconvenience rather than a crisis.

• Plan and rehearse comms redundancy. Every crew should know the primary channel, the backup, and the backup to the backup, and should have keyed up on all of them before they ever need to in anger.
• Keep non-electronic fallbacks alive. Physical maps, printed pre-plans, known addresses, and runner and relay procedures are worth practicing precisely because they do not depend on any signal.
• Do not let navigation become invisible infrastructure. Know which of your systems quietly rely on satellite position and timing, so you understand what degrades if that source is denied or falsified.
• Cross-check location by voice. Treat automatic unit positions as helpful but verify against what crews report, which defeats a false position that no display would flag on its own.
• Write it into your SOPs and comms plan. A resilience habit that lives only in one person's head disappears the day that person is off shift. Put the fallback procedures in writing where every crew can find them.
• Debrief the odd events. When something strange happens, capture it. Patterns across incidents are often only visible when someone bothered to record the one-off.

None of this requires exotic equipment or technical wizardry. It requires deciding in advance that you will not build an operation that quietly assumes the radio and the map will always be there, and then practicing the alternative until it is second nature.

Because this is a sensitive subject, I keep the detailed conversation narrow on purpose. The author, Todd Bowden, will discuss this topic further only with verified public-safety agencies. Agency representatives who want to talk through recognition and response in more depth may request a conversation using the form below and should be prepared to verify their agency affiliation.

Independence notice: RunBoard is an independent operations platform and is not affiliated with, endorsed by, or sponsored by any company, product, network, or agency named in this article. Names are used only for identification and education.