ISO/IEC 20933:2019 This document specifies a framework for a distributed real-time Access system. It includes:
1) an ID triggered modular system architecture, the functions of the modules, the semantics of messages those modules exchange, and elements of messages,
2) the system behaviour from the time it receives an access request until the time it sends the result along with the sequence,
3) performance measurement mechanisms using a time stamping function that can be employed for the evaluation of the system.