METHOD FOR MANAGING COLLISIONS IN A CONTACTLESS DATA EXCHANGING SYSTEM

摘要

This method for managing collisions in a data exchanging system between portable objects, or badges, and at least a data transmitting-receiving terminal, or boundary, co-operating with a plurality of badges simultaneously present in the terminal operating field. It comprises the following successive steps: a) transmission by the terminal, to said plurality of badges, of all call messages with a probability modulation parameter; b) conditional transmission by the badge, to the terminal, of a message in response to the all call message with a probability, less than 100 %, based on the probability modulation parameter in case of collision, this message in response to the all call containing an identifier particular to the badge; c) reception by the terminal of a response message to the all call and in the absence of collision of the latter message with a message transmitted by another badge, setting up of a specific data communication between terminal and badge and proceeding with data exchange, and resumption of step a) for new iteration; d) otherwise, resumption of step a) for new iteration, optionally with dynamic modification of the probability modulation parameter.