METHOD TO PROTECT VEHICLES AGAINST HIGHJACKING Russian patent published in 2010 - IPC B60R25/00 

FIELD: security systems.

SUBSTANCE: every used of vehicle is provided with complete electronic mark (CEM), active in GHz-range and passive in kHz-range. CEM memory stores identification code to be preliminary rewritten into control unit memory and readout unit memory. Note here that readout unit can pump CEM with kHz-range signals. With CEM approaching the vehicle, dynamic identification exchange of radio signals is effected in GHz-range between CEM and control unit. In attempt to penetrate into vehicle passenger compartment and on switching on ignition, dynamic identification exchange of radio signals is effected in kHz-range between CEM and readout unit, after preliminary pumping. Dynamic identification exchange of radio signals allows isolating CEM code and comparing it with code written into control unit and readout unit memories. Code received from CEM coincided with one of those written in readout unit memory and received signal amplitude exceeded preset threshold, control unit is triggered off. Code received from CEM coincided with one written in control unit memory, user identification it taken to be completed. No coincidence, in the case of penetration into vehicle passenger compartment and on switching on ignition, alarm signaling is witched on and vehicle motion is interlocked.

EFFECT: simultaneous use of two different frequency ranges notably reduces probability of highjacking.

3 cl, 2 dwg