The facts about GPS/GSM Jamming

Jamming and Stolen Vehicle Recovery

• Any radio based system is susceptible to attack through jamming but GPS and GSM are particularly vulnerable

• Blocking the GPS / GSM receiver will potentially render a vehicle un-trackable

• Both GPS and GSM jammers are commonly available despite attempts by OfCom to limit their sale. This is not the case for other technologies

• Jamming GSM:– Stops any communication with the service provider (although

locations may still be stored in the unit)– Prevents an approximate location being obtained from the cell site

• Jamming GPS:– Prevents an accurate location being obtained - permanently

• Given the extremely low power levels utilised by GPS, this is the easiest technology of all to defeat

GPS Jamming

• Low-level jamming can completely block satellite signal or induce position errors.

• An airborne 10 Watt battery-powered jammer can cover hundreds of square miles and cost only £40 in parts

• Something much less powerful will prevent car-based systems from operating

• Jammers can be built by people with basic technical competence from readily available commercial components and publicly available information

• GPS Repeaters make excellent jamming devices

• Jammers are readily available from numerous sources

GPS Facts

• 31 active satellites orbiting at 11,000 miles• Fully operational in 1995• Signal strength is 0.0000000000000001 Watts at the receiver – the

equivalent of viewing a 25W light bulb in Los Angeles from London• Signals from at least 4 satellites are needed to determine an

accurate position (latitude, longitude, altitude).• Selective Access (S/A) - the Defense Department originally

reduced position accuracy to 100m for Civilian applications• S/A was turned off in May 2000 and could be reactivated at any

time by the Pentagon• There is some doubt regarding the reliability of the GPS satellite

network going forward

Approaches Used to Defeat Commercial GPS Receivers• Blocking: Damage antenna, or shield

it with metal

• Jamming: Easy to build or buy. complete information is on the Internet)

• Spoofing: Generate fake satellite signals (and therefore fake location

information)

Examples of Portable GPS Simulators & Repeaters

Examples of Portable GPS/GSM Jammers – Available Now!

£35 £70 £215 £59 £97

£26 GPS&GSM £53 GPS&GSM

GPS Issues in SVR Applications

• Reduced number of installation solutions over competing technologies

• Effect of screening by metalwork• Limited view of the sky

– Delays satellite acquisition

– Reduces location accuracy

• Makes covert installations problematic• Antenna orientation problems• Exacerbates Urban Canyoning effect

Jamming - GPS Vs VHF

GPS TRACKER VHF

Jammers Commercially Available Ubiquitous None Known

Published Designs for DIY Devices Yes None Known

Jamming Signal Required Microwatts Tens of Watts

Jamming Signal Subject to Tracking by Police

No Yes

Susceptible to ‘Spoofing’ Yes No

GPS – Future Vulnerability

Source – Los Alamos National Laboratory – Vulnerability Assessment Team

“Signal strength will increase, but there will be no encryption or authentication of the civilian GPS signal until at least 2018, if then.”

Conclusion

• Although GPS/GSM systems have their part to play, there is over-reliance on this technology for Stolen Vehicle Recovery and other security applications

• Current UK standards (Cat 5, TQA etc.) do not recognise the impact of GPS & GSM vulnerability and the increasing availability of jamming devices

• There is growing recognition by the general public and Police of GPS/GSM vulnerability

• The TRACKER / LoJack VHF and other terrestrial systems are far less susceptible to this form of attack and jamming devices are not readily available

• The best approach is a multi-platform solution that provides multiple means of location and communication. Such a system will be far more difficult to defeat using jamming techniques and would require the use of multiple counter-measures. TRACKER Locate will be launched in September 2009 to specifically meet this need.

The Academic Viewpoint………

“Civilian GPS was not designed, and was never intended, for security applications. If you are relying on GPS cargo tracking systems for high level security, you should be aware they are vulnerable to a number of different kinds of attacks, including blocking, jamming, spoofing, and physical attacks. Relatively unsophisticated adversaries can successfully execute all of these attacks”

Roger G. Johnston, Ph.D., CPP & Jon S. Warner, Ph.D. Vulnerability Assessment Team Los Alamos National Laboratory September 2003