Regie Autonome Des Transports Parisiens

Smartdiskette Gmbh

La Regie Autonome Des Transports Parisiens

Innovatron Electronique

Societe Internationale Pour L'innovation S.a.

Francois Grieu

Gr&eacute;gory Mardinian

Stéphane Didier

Frederic Levy

A method of connecting a card to a terminal including the following steps: a) on receiving corresponding respective commands from the terminal, it modifies the contents of the card memory by provisionally recording in the card memory each of said interdependent items of information without losing prior values corresponding to said items; and then b) the modifications are finalized either by all of them being confirmed or by all of them being discarded.

Method for indivisibly modifying a plurality of sites in a microcircuit card non volatile memory, in particular a contactless card

A method manages collisions in a system for interchanging data between portable objects and at least one terminal suitable for co-operating with a plurality of the portable objects simultaneously. The terminal sends out call messages to the portable objects. A portable object conditionally sends a message to the terminal in response to the call with a probability that may be less than 100%, the response containing an identifier specific to the portable object. The receiver receives a response from an identified portable object and in absence of the response colliding with a response sent out by another portable object, a specific data communication link is established between the terminal and the identified portable object. The portable object modulates the probability of response over time depending on whether or not it has itself already responded previously to a call message sent out by the terminal.

Method of managing collisions in a non-contact data interchange system

A method handles collisions in a data interchange between portable objects and at least one data transceiver. The method includes the steps of the transceiver transmitting to said plurality of portable objects general call messages, each including a collision probability modulation parameter. Each portable object conditionally transmits to the transceiver a general call response with a probability of less than 100% as a function of the collision probability modulation parameter and having a specific identifier. The transceiver receives a general call response message, and in the absence of any collision between said message and a message transmitted by another portable object, a specific data communication link is established. Otherwise the method returns to the first step and repeats, optionally modifying the dynamic range of the probability modulation parameter.

Method for managing collisions in a contactless data exchanging system

A system for the exchange of data between a transfer device and an 'intelligent insertable object' that comprises an electronic memory associated with an access circuit and emulates a magnetic recording support with respect to a magnetic read/write head of the transfer device, the data exchange bit rate of the transfer device being greater than that of the circuit providing access to the memory of the insertable object, the system comprising means to limit the bit rate of useful elements in the apparent bit rate of data elements entering and leaving the transfer device, so that it is compatible with the bit rate leaving and entering the circuit providing access to the memory of the insertable object. The system can be applied notably to the exchange of data elements between a microcomputer and an electronic card that can be inserted into the disk drive of the microcomputer or into a memory card reader.

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Paris, France

Francois Grieu