The present document covers the link and sub-network access layers of Very High Frequency (VHF) Digital Link. The present document applies to VDL Mode 2 ground-based stations operating in the VHF band (117,975 MHz to 137,000 MHz) with 25 kHz channel spacing and using Differential Eight Phase Shift Keying (D8PSK).
The present document provides functional specifications for ground-based radio transmitters, receivers, and transceivers intended to be used for ground-air data communications. The present document is derived from the following documents:
• VDL Mode 2 SARPs. ICAO, annex 10 Volume III part I second edition, July 2007;
• ICAO Doc 9776: "Manual on VHF Digital Link (VDL) Mode 2".