ISO/TR 17384:2008 describes the message contents and format of the air interface between the infrastructure and the in-vehicle unit in the Interactive CDRG system.

The air interface message set for route guidance information in the interactive CDRG system in this Technical Report is applicable to both vehicles equipped with an onboard map database and those which are not equipped (i.e., those equipped with simplified graphic output and/or text message display functions).

ISO/TR 17384:2008 covers media independent systems. In this Technical Report, messages required for both cellular phone-based CDRG and beacon-based CDRG are taken into account.