SYSTEM AND TRANSMITTER FOR CONTROLLING ANTI-THEFT TRANSPONDERS

摘要

An improved system for an anti-theft transponder is disclosed. The new system includes, besides a general paged transponder an autonomous low power transmitter device capable of transmitting a specified address code for accessing at least one anti-theft transponder which comprises one receiver module operating on a designated frequency used by a general coverage paging system. A transponder of the system additionally comprises a number of further modules used for the tracking of the device when activated. An anti-theft transponder of the improved system according to the present invention is provided with a first individual access identity intended for authorization of activation by the paging system and at least a second general access identity code will be used for control of a direct activation within a limited coverage of the low power transmitter. A low power transmitter can also be regularly transmitting a general access identity code for a control that the item under surveillance does not illegally leave a site where it is kept.