VHF air-ground and air-air Digital Link (VDL) Mode 4 radio equipment; Technical characteristics and methods of measurement for aeronautical mobile (airborne) equipment; Part 1: Physical layer (V1.2.2)
"The present document applies to the following radio equipment types: ? Very High Frequency (VHF) Digital Link (VDL) Mode 4 aeronautical mobile (airborne) radio transmitters@ transceivers and receivers for air-ground and air-air communications operating in the VHF band@ using Gaussian Filtered Frequency Shift Keying (GFSK) modulation with 25 kHz channel spacing and capable of tuning to any of the 25 kHz channels from 118@000 MHz to 136@975 MHz as defined in ICAO VDL SARPs [2]. The present technical document provides part 1 of the technical specifications. The present document is designed to ensure that equipment certified to it will be compatible with the relevant ICAO VDL SARPs [2] and ICAO VDL4 Technical Manual [1]. Manufacturers should note that in future the tuning range for the transmitter may also cover any 25 kHz channel from 112@000 MHz to 117@975 MHz and the receiver(s) may cover any 25 kHz channel from 108@000 MHz to 117@975 MHz. The present document applies to ""aeronautical mobile (airborne and in some cases ground vehicles)"" equipment which will hereinafter be referred to as ""mobile"" equipment. The scope of the present document is limited to mobile stations. The equivalent specification for ground stations is EN 301 842 [10]. The VDL Mode 4 system provides digital communication exchanges between aircraft and ground-based systems and other aircraft supporting surveillance and communication applications. The supported modes of communication include: ? broadcast and point-to-point communication; ? broadcast services including Automatic Dependent Surveillance - Broadcast (ADS-B)@ Traffic Information Service - Broadcast (TIS-B) and Flight Information Service - Broadcast (FIS-B) capabilities; ? air-air and ground-air services; ? operation without ground infrastructure. The present document is derived from the specifications: ? ICAO VDL4 Technical Manual [1] and ICAO VDL SARPs [2] produced under the auspices of the International Civil Aviation Organization (ICAO). ? Other relevant standards as defined in clause 2. It is envisaged that manufacturers may provide equipment supporting: ? broadcast services only; ? point-to-point services only; ? both broadcast and point-to-point services. The present document deals with tests of the physical layer necessary to support all types of equipment. The present document includes: ? clause 2 provides references to relevant documents; ? clause 3 provides general definitions@ abbreviations and symbols used; ? clause 4 provides a general description and architecture of VDL Mode 4; ? clause 5 provides functional specifications applicable to the physical layer including transmitter eceiver requirements and the modulation scheme; ? clause 6 provides VDL Mode 4 equipment requirements; ? clause 7 provides general design requirements; ? clause 8 provides environmental test requirements; ? clause 9 provides detailed test procedures for the physical layer; ? clause 10 provides installed equipment requirements; ? annex A provides a detailed cross-reference to the relevant requirements contained in reference [1]; ? annex B provides an assessment of VDL Mode 4 Link Budget; ? annex C provides a Bibliography; ? a document history. The full physical layer tests are provided which correspond closely to the standard set of tests used for other VDL systems. NOTE: Flight tests are defined in EN 302 842-2 [7]. Mandating and recommendation phrases a) ""Shall"" - The use of the word ""Shall"" indicates a mandated criterion; e.g. compliance with the particular procedure or specification is mandatory and no alternative may be applied. b) ""Should"" - The use of the word ""Should"" (and phrases such as ""It is recommended that...""@ etc.) indicate that though the procedure or criterion is regarded as the preferred option@ alternative procedures@ specifications or criteria may be applied@ provided that the manufacturer@ installer or tester can provide information or data to adequately support and justify the alternative."