Field devices are a key component in intelligent transport systems (ITS). Field devices include traffic signals, message signs, weather stations, traffic sensors, roadside equipment for connected ITS (C-ITS) environments, etc.

Field devices often need to exchange information with other external entities (managers). Field devices can be quite complex, necessitating the standardization of many data concepts for exchange. As such, the ISO 20684 series is divided several individual parts.

This document specifies user needs, requirements and design elements that are normatively used by other parts of the ISO 20684 series. Specifically, it defines an internal field device clock, a mechanism for grouping object values together to provide for more efficient transfer of data, and it provides formal requirements for the SNMP target and target parameters as defined in IETF RFC 3413.