Security devices for personal identification: Contactless proximity devices — Part 3: Initialization and anti-collision

This document establishes technical requirements for the initial communication and collision avoidance mechanisms within non-contact proximity systems used for identity identification. It defines the protocols that enable a reader to detect and select multiple nearby cards operating in the same frequency field without data loss. The specification outlines the physical layer characteristics, ensuring reliable data exchange during the activation phase. It details the procedures for anti-collision algorithms, which are critical when multiple devices are present simultaneously. These procedures allow the system to uniquely identify each card before data transmission begins. The document specifies signal modulation and timing constraints necessary for interoperability between different manufacturers' equipment. It serves as a framework for ensuring secure and efficient interaction in access control, payment, and electronic identification applications. The content focuses exclusively on the procedural and technical aspects required to initiate and maintain stable communication links in proximity environments.