COLLISION DETECTION AND AVOIDANCE SCHEME FOR CONTACTLESS CARD PAYMENT SYSTEMS

摘要

An electronic payment system for conducting transactions by presenting a contactless payment card to a card reader. The card reader is configured to process transactions when only one card is present in its operating field, The card reader uses collision detection and avoidance algorithms (302-309) to detect and report (309) instances where multiple cards are present in the operating field. In response to a reported collision, the collision may be cleared by manual intervention, i.e., by physically removing excess cards from the reader's operating field.