A South African vehicle tracking and fleet management company, Pulsit Electronics, has developed a system it believes could help weaken the scourge of truck hijackings in Southern Africa. It works by countering the signal jamming devices criminals use to block vehicle tracking systems.

Pulsit Electronics chief financial and information officer Bokkie Fourie explains that hijackers use a range of jamming systems — some of them quite sophisticated, others less so — to block tracking systems from communicating via the cellular networks or via satellite. Once jammed, they typically either hijack the vehicle or work in cahoots with the driver and move it to another location where they offload its precious cargo.

But Pulsit’s system, which took about six months from conception to final development, is able to identify when frequency jammers are being used and, if detected, will put a vehicle into a disabled state in which it can’t be driven.

Though the driver is still able to control the vehicle’s power steering and brakes in this state, he isn’t able to accelerate until the jamming signal is switched off. An alert can also be sent to a central office, prompting an agent to try to call the driver and, if necessary, to call in a response team.

Fourie says signal jamming is a big headache for logistics companies in Southern Africa. Pulsit installed its first commercial version of its jamming mitigation system last month and Fourie claims a number of logistics firms have approached the company interested in using it in their fleets.

Fourie explains that the system is able to determine when tracking signals are being jammed. It does this by measuring signal characteristics to determine if there is deterioration through noise in the frequency bands they use.

“When jamming happens, we induce the disabled state, which inhibits acceleration. The truck can idle — it can gear down and park — but it can’t go anywhere.”

If the tracking system is able to filter through the noise sufficiently, it will transmit its normal position and a distress signal with details of the jamming event. Even if the tracking device is unplugged, the vehicle will remain in the disabled state. Fourie says it’s virtually impossible to disable the limp mode, but he declines to explain in detail how it works, saying it’s a trade secret.

Fleet owners can decide whether or not to alert potential hijackers that their trucks are fitted with the system by placing a notice to this effect on their vehicles.

Pulsit Electronics is now developing a similar system for trailers for instances where hijackers, for example, remove the trailer and hook it up to another truck and then force the driver to drive his now trailer-less vehicle along his usual route to fool the tracking system and those monitoring it.