Patent ID: 7496448
Filing Date: 2009-02-24
Classification: G01C,H04H

Abstract:
1. A method for extracting traffic information data from traffic information in encrypted form in_broadcast radio signals, comprising: providing a storage medium, having a writable portion for storing data, and having a structure unalterably storing a storage medium serial number formed in the manufacture of the storage medium; providing a navigation unit having a radio receiver for receiving the broadcast radio signals and a reader for reading the writable portion of the storage medium and for reading the structure unalterably storing a storage medium serial number formed in the manufacture of the storage medium; arranging said storage medium with said navigational unit; reading said storage medium serial number from said storage medium, at the navigational unit; inputting a given license number data to the navigational unit; generating an access code, at the navigational unit, based on said reads storage medium number and said input license number; determining whether or not said generated access code meets a given access code admissibility criterion; and extracting the traffic information data from the encrypted traffic information if said determining determines the access code admissibility criterion is met, else not extracting the traffic information data.