scope:

The present document applies to VDL Mode 2 ground-air digital communications using Differential Eight Phase Shift Keying (D8PSK), intended for channel increments of 25 kHz. The VDL Mode 2 system provides data communication exchanges between aircraft and ground-based systems. The scope of the present document is limited to ground-based stations.

The present document provides functional specifications for ground-based radio equipment intended to be used for ground-air data communications. The present document is derived from the following documents:

• Annex 10 of the ICAO Convention on International Civil Aviation [1].
• ED 92B [i.2]: "MOPS for an Airborne VDL Mode-2 Transceiver Operating in the frequency range 118-136.975 MHz" (2012), which specifies the airborne transceiver.

The present document consists of two parts:

• the first part provides functional specifications and test procedures for physical layer and MAC sub-layer;
• the second part provides functional specifications and test procedures for link and sub-network access layers.