What Is a GPS Jammer? Detection and Protection in the Philippines

These days, having movements tracked online and in the real world is becoming more common. For businesses especially, there is a long list of GPS tracking benefits, including improved routing, real-time vehicle monitoring and greater accountability.

While many people are willing to share their location for good purposes, unauthorised access or the use of GPS jammer can pose serious risks to fleet security. That’s why it’s important to choose GPS solutions that prioritise data protection, reliability and proactive threat detection.

What is a GPS jammer?

A GPS jammer is a typically small, self-contained transmitter device used to conceal one’s location by sending radio signals with the same frequency as a GPS device. When this occurs, even the best GPS device is unable to determine its position due to interference.

The relatively low power and quick start-up time allow the jammers to be used only when required. Although illegal, various types of cheap GPS blockers are available for purchase online, such as:

• Physical shields
• Wi-Fi/Bluetooth jammers
• Remote control jammers
• Spy camera jammers
• Drone jammers

How a GPS jammer works

Here’s how a typical GPS jammer operates to interfere with tracking devices:

1. The user plugs the jammer into the automotive auxiliary power outlet.
2. The jammer is placed close to the installed GPS tracker.
3. When active, the GPS jammer generates an interference signal over a 5 to 10 metre (16 to 33 feet) radius to disrupt reception of the GPS satellite signal.

To understand how a jammer functions, it is also helpful to know how the Global Positioning System (GPS) works.

A GPS tracker receives microwave signals from an array of satellite transmitters orbiting the Earth. Once the tracker receives signals from four or more satellites, it determines its position through a series of time calculations and trilateration.

The receiver relies on these precise and specific satellite signals to determine where it is in the world. The GPS tracking device then transmits this position and velocity information to a monitoring location, usually sent over the cellular network.

In some cases, satellite malfunction or solar flares Open in new window can temporarily disrupt the transmission of GPS signals.

A GPS jammer is different in that it sends out radio signals or signal noise with the same frequency as the GPS device to override or distort the GPS satellite signals.

When this occurs, the GPS device can no longer calculate its position because the satellite signal is masked by the interference.

GPS jamming vs. spoofing

While both GPS jamming and spoofing interfere with location tracking, they do so in different ways.

Jamming disrupts the signal completely, while spoofing deceives the receiver with fake data.

Who uses GPS jammers?

The reasons for using jammers vary. Originally created by the government, GPS jammers were designed for military use.

Concealing vehicle location can be crucial to the success of a mission. The devices act as a cloak, giving the military privacy, increased safety and an overall advantage in high-risk situations.

Other uses include:

• Speeding drivers trying to prevent detection by police
• Criminals using GPS jammers to cover vehicle thefts
• Trucking fleet drivers hiding their location from employers

Are GPS jammers legal in the Philippines?

A GPS jammer should not be used by private individuals or fleet operators in the Philippines. The National Telecommunications Commission (NTC) prohibits the sale, purchase, importation, possession and use of cellular phone jamming devices under NTC Memorandum Order No. 001-02-2010 Open in new window

GPS jammers also transmit radio-frequency interference, which may fall under the Philippines’ broader radio-frequency and telecommunications regulations, including Republic Act No. 7925 Open in new window, Executive Order No. 546 Open in new window and Republic Act No. 3846 Open in new window.

Potential consequences may include equipment confiscation, suspension or revocation of authorisations and further legal action. Philippine legislation does not provide a single, clearly verified nationwide fine specifically for GPS jammer use, so organisations should not publish a fixed penalty amount without legal review.

For fleet operators, an unexpected loss of GPS data should be investigated through legitimate causes such as poor cellular coverage, antenna problems, device faults or radio-frequency interference. Do not install or use a jammer. For guidance on a specific device or use case, contact the NTC or qualified Philippine legal counsel.

How do GPS jammers affect Philippine transport and fleet operations?

For Philippine transport operators and regulators, GPS jammers create both an operational and public-safety risk. Jamming disrupts satellite signals used by vehicle tracking, fleet management and telematics systems, making it harder for companies to monitor vehicles and respond to incidents.

Philippine fleets use telematics to monitor:

- Vehicle location and route progress

- Fuel consumption and excessive idling

- Driver behaviour and safety events

- Engine health and maintenance needs

- Delivery schedules and asset utilisation

When a jammer blocks or interferes with these signals, a vehicle may appear offline, stop reporting its location or produce incomplete trip data. This can delay dispatch decisions, weaken incident investigations and reduce visibility during theft, breakdowns or emergencies.

The risk extends beyond fleet operations. Radio-frequency interference can affect other communications and navigation systems, particularly around roads, ports and airports. The National Telecommunications Commission (NTC) Open in new window prohibits the sale, purchase, importation, possession and use of cellular jamming devices. Related radio-frequency and telecommunications rules also apply under Republic Act No. 7925 Open in new window, Executive Order No. 546 Open in new windowand Republic Act No. 3846 Open in new window.

Fleet operators should never use a jammer to hide a vehicle’s location or avoid monitoring. Unexpected tracking gaps should instead be investigated through legitimate causes such as weak cellular coverage, antenna problems, device faults or possible radio-frequency interference.

How to use Geotab for GPS jamming detection

Fleets can use Geotab solutions to minimise the negative effects of GPS blockers and keep drivers from flying under the radar. When a GPS signal is not received, the Trips History map will show a missing or interrupted trip, calling attention to an issue.

If GPS jamming occurs mid-trip, a straight line will be displayed from when jamming starts to the point where the jamming device is turned off.

Anyone monitoring the vehicle will quickly see this and can investigate the cause of the missing trip information.

There may be other reasons for loss of GPS data besides GPS jamming, like a radio that’s not working properly.

A straight line in MyGeotab indicates GPS disruption.

The GPS module in newer Geotab GO units has a jamming detection function that triggers the device to report a debug log. Fleet managers can see this in the MyGeotab log details as: “GpsJammingDetected.”

Set up alerts for GPS jamming

Geotab users can automate detection by creating a Log Data & Collisions report Open in new window

in MyGeotab and setting it to be sent only when at least one event is detected. When GPS jamming occurs, the report will be sent via email as an alert, prompting further investigation.

It’s important to note that even when a GPS jammer disrupts GPS receiver functionality, all other functions are unaffected. Despite the lost GPS connection, the Geotab GO device will continue to gather and send critical vehicle-related data such as engine data, driver behaviour, error codes and auxiliaries.

Geotab is dedicated to maintaining a robust and stable system and will continue to make the GO devices as tamper-proof as possible.

GPS jamming protection with Geotab

GPS blockers can compromise fleet safety, visibility and compliance. With Geotab, fleets gain powerful tools for detecting signal interference in real time, alerting managers and preserving critical fleet data even during disruptions.

By investing in secure driver tracking and tamper-resistant technology, fleets can stay ahead of threats and ensure their operations run smoothly, no matter what interference comes their way.