METHOD, ELECTRONIC COVER, AND ACCESS UNIT FOR PROVIDING ACCESS TO A ZONE BY MEANS OF A CARD

摘要

Standard electronic cards (1) such as proximity cards can transmit data to a reading unit PCD within a range of about 1 to 10 cm. Boosters which essentially represent a radio extension are used for improving comfort. However, this is not satisfactory regarding autonomy and reliability of the communication across 30 to 50 meters, for example. This problem is solved by means of the inventive method featuring a card (1) that is inserted into an electronic cover (20). According to said method, the cover (20) is first switched to an active state in a transit zone (50) with the aid of an electromagnetic field (42), whereby a bi-directional communication (25) is initiated to transmit a tag. An unblocking signal is generated if the transmitted tag matches a stored tag such that access to a protected zone is authorized via the transit zone (50).