VHF air-ground Digital Link (VDL) Mode 2; Technical characteristics and methods of measurement for ground-based equipment; Part 1: Physical layer and MAC sub-layer (V1.3.1)
"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 VDL Mode 2 system is designed to be a Ground/Air sub-system of the Aeronautical Telecommunication Network (ATN) using the AM(R)S band and it is organized according to the Open Systems Interconnection (OSI) model (defined by ISO). It shall provide reliable subnetwork services to the ATN system. 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: ? VDL Mode 2 SARPs version 3.0. ICAO Annex 10 Volume III part I [2]. ? ED 92a [3]: ""MOPS for an Airborne VDL Mode-2 Transceiver Operating in the frequency range 118-136.975 MHz"" (2003)@ 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."