M/318 -

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 130 [i.2].
The present technical document provides part 3 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 [i.2] and ICAO VDL4 Technical Manual [i.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 [4], [5], [6] and [7].
A description of the scope of the VDL Mode 4 system is provided in part 2 of these technical specifications (see EN 302 842-2 [2], clause 1).
EN 302 842-1 [1] deals with tests of the physical layer. EN 302 842-2 [2] deals with tests of the link layer sufficient to support broadcast functionality including requirements and tests sufficient to recognize and respond to transmissions associated with point-to-point communication. The present document provides technical specifications for a VDL Mode 4 mobile transceiver supporting a full Automatic Dependent Surveillance-Broadcast (ADS-B) capability and, optionally, the additional functionality of either, or a combination of, the following services:
Traffic Information Service-Broadcast (TIS-B);
Flight Information Service-Broadcast (FIS-B);
GNSS Augmentation Service-Broadcast (GNS-B).
The TIS-B, FIS-B, or GNS-B reception processing functionality in the airborne equipment is expected to be provided by a TIS-B, FIS-B or GNS-B processor, which could be contained within the VDL Mode 4 transceiver, but could also be housed in a separate physical unit. Therefore to support TIS-B, FIS-B or GNS-B message reception, the minimum functionality demanded of a basic VDL Mode 4 airborne transceiver unit (i.e. one that does not have a TIS-B, FIS-B or GNS-B processor housed within it) is to pass to the TIS-B, FIS-B or GNS-B processor, all TIS-B, FIS-B or GNS-B messages received.
As the measured values of equipment performance may be a function of the method of measurement, standard test conditions and methods of test are recommended in the present document.

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 [i.2].
The present document provides part 2 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 [i.2] and ICAO VDL4 Technical Manual [i.1].
NOTE: In clause 5.1.4, Tertiary time, as described by the ICAO VDL4 Technical Manual [i.1], has not been included as a requirement in the present document due to the opinion of the ETSI Working Group that insufficient evidence was available to be able to verify correct operation of a "floating network" of stations operating on tertiary time.
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], [11], [12] and [13].
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), Flight Information Service - Broadcast (FIS-B) capabilities and GNSS Augmentation Service - Broadcast (GNS-B);
air-air and ground-air services;
operation without ground infrastructure.
VDL Mode 4 is designed to be an Air/Ground subsystem of the Aeronautical Telecommunication Network (ATN) (see ICAO ATN SARPs [i.3]) using the AM(R)S band and it is organized according to the Open Systems Interconnection (OSI) model (defined by ISO). It provides reliable sub network services to the ATN system. Other networks can also be supported but have not been the focus of the present document.
The present document is derived from the standards and specifications in:
ICAO VDL4 Technical Manual [i.1] 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.
EN 302 842-1 [2] deals with tests of the physical layer. The present document defines the core link layer requirements for the VDL Mode 4 mobile station necessary to support all types of equipment. This includes a simple position broadcast functionality.
The present document deals with tests of the link layer sufficient to support core link layer functionality, and it also includes requirements and tests sufficient to recognize and respond to transmissions associated with point-to-point communication. The present document does not address requirements for the full ADS-B message set, or for other broadcast applications that can be supported by the VDL Mode 4 equipment. These are covered by EN 302 842-3 [6].

REN/AERO-00007-2

REN/AERO-00007-3

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/receiver
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].

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 document provides part 4 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 as applicable also 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 [4]. A description of the scope of the VDL Mode 4 system is provided in part 2 of EN 302 842-2 [6], clause 1. EN 302 842-1 [5] deals with tests of the physical layer, EN 302 842-2 [6] deals with core link layer functionality and EN 302 842-3 [7] with additional broadcast functionality. The present document deals with tests of the datalink layer (DLS) and the link layer sufficient to support point-to-point functionality. Note that, as described in EN 302 842-2 [6], a system supporting point-to-point functionality is required to conform to EN 302 842-1 [5], EN 302 842-2 [6] and the specification in the present document. The present document includes:
- clause 2 provides references to relevant documents;
- clause 3 provides general definitions, abbreviations and symbols used;
- clause 4 describes the VDL Mode 4 mobile station point-to-point functions;
- clause 5 provides performance specifications for the VDL Mode 4 mobile station;
- clause 6 provides general design requirements;
- clause 7 provides protocol tests for the point-to-point functions of the system;
- annex A provides a detailed cross-reference to the relevant requirements contained in
ICAO VDL4 Technical Manual [1];
- annex B provides a bibliography;
- a document history.
Note that the system can support a very wide range of functions. It is not practical to provide specific tests for all aspects of functionality. The approach used is to provide detailed tests for the core point-to-point functionality and to provide tests of those remaining requirements which, if wrongly implemented, could cause a deterioration in the service offered by other VDL Mode 4 stations.
Mandating and Recommendation Phrases
a) "Shall":
- The use of the word "Shall" indicates a mandated criterion; i.e. 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.) indicates 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.

REN/AERO-00007-1

REN/AERO-00007-4

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 document provides part 2 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] and with the SES 552/2004 interoperability Regulation. NOTE: In clause 5.1.4, Tertiary time, as described by the ICAO VDL4 Technical Manual [1], has not been included as a requirement in the present document due to the opinion of the ETSI Working Group that insufficient evidence was available to be able to verify correct operation of a "floating network" of stations operating on tertiary time. 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 [15]. 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), Flight Information Service - Broadcast (FIS-B) capabilities and GNSS Augmentation Service - Broadcast (GNS-B); -air-air and ground-air services; -operation without ground infrastructure. VDL Mode 4 is designed to be an Air/Ground subsystem of the Aeronautical Telecommunication Network (ATN) (see ICAO ATN SARPs [8]) using the AM(R)S band and it is organized according to the Open Systems Interconnection (OSI) model (defined by ISO). It provides reliable sub network services to the ATN system. Other networks can also be supported but have not been the focus of the present document. The present document is derived from the standards and specifications in: -ICAO VDL4 Technical Manual [1] 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 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] and with the SES 552/2004 interoperability Regulation [9]. 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/receiver requirements and the modulation scheme.

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 document provides part 4 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] and with the SES 552/2004 interoperability Regulation [9]. 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 as applicable also 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 [4]. A description of the scope of the VDL Mode 4 system is provided in part 2 of EN 302 842-2 [6], clause 1. EN 302 842-1 [5] deals with tests of the physical layer, EN 302 842-2 [6] deals with core link layer functionality and EN 302 842-3 [7] with additional broadcast functionality. The present document deals with tests of the datalink layer (DLS) and the link layer sufficient to support point-to-point functionality. Note that, as described in EN 302 842-2 [6], a system supporting point-to-point functionality is required to conform to EN 302 842-1 [5], EN 302 842-2 [6] and the specification in the present document. The present document includes: -clause 2 provides references to relevant documents; -clause 3 provides general definitions, abbreviations and symbols used; -clause 4 describes the VDL Mode 4 mobile station point-to-point functions; -clause 5 provides performance specifications for the VDL Mode 4 mobile station; -clause 6 provides general design requirements; -clause 7 provides protocol tests for the point-to-point functions of the system; -annex A provides a detailed cross-reference to the relevant requirements contained in ICAO VDL4 Technical Manual [1]; -annex B provides a description of compliance with the SES 552/2004 Regulation [9]; -annex C provides a bibliography; -a document history. Note that the system can support a very wide range of functions. It is not practical to provide specific tests for all aspects of functionality. The approach used is to provide detailed tests for the core point-to-point functionality and to provide tests of those remaining requirements which, if wrongly implemented, could cause a deterioration in the service offered by other VDL Mode 4 stations.

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 130 [2]. The present technical document provides part 3 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] and with the SES 552/2004 interoperability Regulation [10]. 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 [9]. A description of the scope of the VDL Mode 4 system is provided in part 2 of these technical specifications (see EN 302 842-2 [5] clause 1). EN 302 842-1 [4] deals with tests of the physical layer. EN 302 842-2 [5] deals with tests of the link layer sufficient to support broadcast functionality including requirements and tests sufficient to recognize and respond to transmissions associated with point-to-point communication. The present document provides technical specifications for a VDL Mode 4 mobile transceiver supporting a full Automatic Dependent Surveillance-Broadcast (ADS-B) capability and, optionally, the additional functionality of either, or a combination of, the following services: -Traffic Information Service-Broadcast (TIS-B); -Flight Information Service-Broadcast (FIS-B); -GNSS Augmentation Service-Broadcast (GNS-B). The TIS-B, FIS-B, or GNS-B reception processing functionality in the airborne equipment is expected to be provided by a TIS-B, FIS-B or GNS-B processor, which could be contained within the VDL Mode 4 transceiver, but could also be housed in a separate physical unit. Therefore to support TIS-B, FIS-B or GNS-B message reception, the minimum functionality demanded of a basic VDL Mode 4 airborne transceiver unit (i.e. one that does not have a TIS-B, FIS-B or GNS-B processor housed within it) is to pass to the TIS-B, FIS-B or GNS-B processor, all TIS-B, FIS-B or GNS-B messages received. As the measured values of equipment performance may be a function of the method of measurement, standard test conditions and methods of test are recommended in the present document. The present document is organized as follows: -clause 2 provides references to relevant documents; -clause 3 provides general definitions, abbreviations and symbols used; -clause 4 describes the VDL Mode 4 mobile station functionality to support ADS-B, TIS-B, FIS-B and GNS-B; -clause 5 provides performance specifications for the VDL Mode 4 mobile station supporting ADS-B, TIS-B, FIS-B and GNS-B Services; -clause 6 provides general design requirements.

The present document applies to the following radio equipment types:
1) Very High Frequency (VHF) Digital Link (VDL) Mode 4 ground-based radio transmitters and receivers for air-ground 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 VHF Digital Link (VDL) Standards and Recommended Practices (SARPs) [8]. The present document provides part 4 of the technical specifications. The present document is designed to ensure that equipment certified to it will be compatible with the relevant ICAO VHF Digital Link (VDL) Standards and Recommended Practices (SARPs) [8] and VDL Mode 4 Technical Manual (TM) [1] and with the SES 552/2004 interoperability Regulation [10]. Manufacturers should note that in future the tuning range for the ground transceivers may also cover any 25 kHz channel from 108,000 MHz to 117,975 MHz. The scope of the present document is limited to ground stations. The equivalent specification for airborne stations is EN 302 842 [7]. A description of the scope of the VDL Mode 4 system is provided in part 2 of these technical specifications (see EN 301 842-2 [5], clause 1). EN 301 842-1 [4] deals with tests of the physical layer, EN 301 842-2 [5] deals with core link layer functionality and EN 301 842-3 [6] with additional broadcast functionality. The present document deals with tests of the datalink service (DLS) layer and the link layer sufficient to support point-to-point functionality. Note that, as described in EN 301 842-2 [5], a system supporting point-to-point functionality is required to conform to EN 301 489-22 [2], EN 301 842-1 [4], EN 301 842-2 [5] and the specification in the present document. The present document is organized as follows:
clause 2 provides references to relevant documents;
clause 3 provides general definitions, abbreviations and symbols used;
clause 4 describes the VDL Mode 4 ground station point-to-point functions;
clause 5 provides performance specifications for the VDL Mode 4 ground station;
clause 6 provides general design requirements;
clause 7 provide protocol tests for the point-to-point functions of the system;
annex A provides a detailed cross-reference to the relevant requirements contained in [1];
annex B provides a Bibliography;
a document history.
Note that the system can support a very wide range of functions. It is not practical to provide specific tests for all aspects of functionality. The approach used is to provide detailed tests for the core point-to-point functionality and to provide tests of those remaining requirements which, if wrongly implemented, could cause a deterioration in the
service offered by other VDL Mode 4 stations.

REN/ERM-TG25-030-3

REN/ERM-TG25-030-2

REN/ERM-TG25-030-1

REN/ERM-TG25-030-4

REN/ERM-TG25-029-4

The present document provides part 3 of the technical specifications for 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 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 [9]. A description of the scope of the VDL Mode 4 system is provided in part 2 of these technical specifications (see
EN 302 842-2 [5] clause 1). EN 302 842-1 [4] deals with tests of the physical layer. EN 302 842-2 [5] deals with tests of the link layer sufficient to support broadcast functionality including requirements and tests sufficient to recognize and respond to transmissions associated with point-to-point communication. The present document provides technical specifications for a VDL Mode 4 mobile transceiver supporting a full Automatic Dependent Surveillance - Broadcast (ADS-B) capability and,
optionally, the additional functionality of either, or a combination of, the following services:
• Traffic Information Service - Broadcast (TIS-B);
• Flight Information Service - Broadcast (FIS-B);
• GNSS Augmentation Service - Broadcast (GNS-B).
The TIS-B, FIS-B, or GNS-B reception processing functionality in the airborne equipment is expected to be provided by a TIS-B, FIS-B or GNS-B processor, which could be contained within the VDL Mode 4 transceiver, but could also be housed in a separate physical unit. Therefore to support TIS-B, FIS-B or GNS-B message reception, the minimum functionality demanded of a basic VDL Mode 4 airborne transceiver unit (i.e. one that does not have a TIS-B, FIS-B or GNS-B processor housed within it) is to pass to the TIS-B, FIS-B or GNS-B processor, all TIS-B, FIS-B or GNS-B messages received. As the measured values of equipment performance may be a function of the method of measurement, standard test conditions and methods of test are recommended in the present document.

The present document provides part 1 of the technical specifications, and means of testing compliance, for 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 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]. NOTE 1: In clause 6.1.12 the requirement is more stringent than required in ICAO VDL SARPs [2]. 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 [8].
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:
• References, definitions, abbreviations and symbols are provided in clauses 2 and 3.
• Clause 4 provides a general description and architecture of VDL Mode 4.
• Clause 5 provides functional specifications applicable to the physical layer including transmitter/receiver 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.
The full physical layer tests are provided which correspond closely to the standard set of tests used for other VDL systems.
NOTE 2: 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.

The present document provides part 4 of the technical specifications for Very High Frequency (VHF) Digital Link (VDL) Mode 4 ground-based radio transmitters and receivers for air-ground 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 VHF Digital Link (VDL) Standards and Recommended Practices (SARPs) [8]. The present document is designed to ensure that equipment certified to it will be compatible with the relevant ICAO VHF Digital Link (VDL) Standards and Recommended Practices (SARPs) [8] and VDL Mode 4 Technical Manual (TM) [1]. Manufacturers should note that in future the tuning range for the ground transceivers may also cover any 25 kHz channel from 108,000 MHz to 117,975 MHz.
The scope of the present document is limited to ground stations. The equivalent specification for airborne stations is EN 302 842 [7]. A description of the scope of the VDL Mode 4 system is provided in part 2 of these technical specifications (see EN 301 842-2 [5], clause 1). EN 301 842-1 [4] deals with tests of the physical layer, EN 301 842-2 [5] deals with core link layer functionality and EN 301 842-3 [6] with additional broadcast functionality. The present document deals with tests of the datalink layer (DLS) and the link layer sufficient to support point-to-point functionality. Note that, as described in EN 301 842-2 [5], a system supporting point-to-point functionality is required to conform to EN 301 489-22 [2], EN 301 842-1 [4], EN 301 842-2 [5] and the specification in the present document.
The present document includes:
• references, definitions, abbreviations and symbols are provided in clauses 2 and 3;
• clause 4 describes the VDL Mode 4 ground station point-to-point functions;
• clause 5 performance specifications for the VDL Mode 4 ground station;
• clause 6 provides general design requirements;
• clause 7 provide protocol tests for the point-to-point functions of the system;
• a document history is contained in clause 8;
• clause A provides a detailed cross-reference to the relevant requirements contained in [1].
Note that the system can support a very wide range of functions. It is not practical to provide specific tests for all aspects of functionality. The approach used is to provide detailed tests for the core point-to-point functionality and to provide tests of those remaining requirements which, if wrongly implemented, could cause a deterioration in the service offered by other VDL Mode 4 stations.
Mandating and Recommendation Phrases
a) "Shall":
- the use of the word "Shall" indicates a mandated criterion; i.e. 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.) indicates 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.

The present document provides part 3 of the technical specifications for Very High Frequency (VHF) Digital Link (VDL) Mode 4 ground-based radio transmitters and receivers for air-ground 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 VHF Digital Link (VDL) Standards and Recommended Practices (SARPs) [10]. The present document is designed to ensure that equipment certified to it will be compatible with the relevant ICAO VHF Digital Link (VDL) Standards and Recommended Practices (SARPs) [10] and VDL Mode 4 Technical Manual (TM) [1]. Manufacturers should note that in future the tuning range for the ground transceivers may also cover any 25 kHz channel from 108,000 MHz to 117,975 MHz. The scope of the present document is limited to ground stations. The equivalent specification for airborne stations is EN 302 842 [9]. A description of the scope of the VDL Mode 4 system is provided in part 2 of these technical specifications (see EN 301 842-2 [5] clause 1). EN 301 842-1 [4] deals with tests of the physical layer. EN 301 842-2 [5] deals with tests of the link layer sufficient to support broadcast functionality including requirements and tests sufficient to recognize and respond to transmissions associated with point-to-point communication. The present document provides technical specifications for a VDL Mode 4 ground-based transceiver supporting a full Automatic Dependent Surveillance - Broadcast (ADS-B) capability and, optionally, the additional functionality of either, or a combination of, the following services:
• Traffic Information Service - Broadcast (TIS-B);
• Flight Information Service - Broadcast (FIS-B);
• GNSS Augmentation Service - Broadcast (GNS-B).
The TIS-B, FIS-B, or GNS-B functionality in the ground-based equipment is expected to be provided by a TIS-B, FIS-B or GNS-B processor, which could be contained within the VDL Mode 4 transceiver, but could also be housed in a separate physical unit. Therefore to support TIS-B, FIS-B or GNS-B, the minimum functionality demanded of a basic VDL Mode 4 ground-based transceiver unit (i.e. one that does not have a TIS-B, FIS-B or GNS-B processor housed within it) is to receive, from the TIS-B, FIS-B or GNS-B processor, all messages to be transmitted, and to transmit them. In the case of FIS-B there is an additional requirement to receive report request messages (from other VDL4 stations) and to pass those messages to the FIS-B processor. It should be noted that the specifications for TIS-B, FIS-B and GNS-B in the present document represent a first step towards defining these applications, based on the work carried out as part of the NUP and MEDUP Programmes, and changes to the specifications for these services may therefore occur in the future.

The present document provides part 2 of the technical specifications for 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 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].
NOTE: In clause 5.1.4, Tertiary time, as described by the ICAO VDL4 Technical Manual [1], has not been included as a requirement in the present document due to the opinion of the ETSI Working Group that insufficient evidence was available to be able to verify correct operation of a "floating network" of stations operating on tertiary time. 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 [13].
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), Flight Information Service - Broadcast (FIS-B) capabilities and GNSS Augmentation Service - Broadcast (GNS-B);
• air-air and ground-air services;
• operation without ground infrastructure.
VDL Mode 4 is designed to be an Air/Ground subsystem of the Aeronautical Telecommunication Network (ATN) (see ICAO ATN SARPs [8]) using the AM(R)S band and it is organized according to the Open Systems Interconnection (OSI) model (defined by ISO). It provides reliable sub network services to the ATN system. Other networks can also be supported but have not been the focus of the present document. The present document is derived from the standards and specifications in:
• ICAO VDL4 Technical Manual [1] 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.
EN 302 842-1 [4] deals with tests of the physical layer. The present document defines the core link layer requirements for the VDL Mode 4 mobile station necessary to support all types of equipment. This includes a simple position broadcast functionality.
The present document deals with tests of the link layer sufficient to support core link layer functionality, and it also includes requirements and tests sufficient to recognize and respond to transmissions associated with point-to-point communication. The present document does not address requirements for the full ADS-B message set, or for other broadcast applications that can be supported by the VDL Mode 4 equipment. These are covered by EN 302 842-3 [9].
Detailed requirements for point-to-point communication are beyond the scope of the present document, but can be found in EN 302 842-4 [10]. EN 302 842-4 [10] also includes the interface to the Aeronautical Telecommunication Network (ATN) as defined in ICAO ATN SARPs [8].

The present document provides part 4 of the technical specifications for 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 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 as applicable also 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 [4]. A description of the scope of the VDL Mode 4 system is provided in part 2 of these technical specifications (see EN 302 842-2 [6], clause 1). EN 302 842-1 [5] deals with tests of the physical layer, EN 302 842-2 [6] deals with core link layer functionality and EN 302 842-3 [7] with additional broadcast functionality. The present document deals with tests of the datalink layer (DLS) and the link layer sufficient to support point-to-point functionality. Note that, as described in EN 302 842-2 [6], a system supporting point-to-point functionality is required to conform to EN 302 842-1 [5], EN 302 842-2 [6] and the specification in the present document.
The present document includes:
• references, definitions and abbreviations are provided in clauses 2 and 3;
• clause 4 describes the VDL Mode 4 mobile station point-to-point functions;
• clause 5 performance specifications for the VDL Mode 4 mobile station;
• clause 6 provides general design requirements;
• clause 7 provides protocol tests for the point-to-point functions of the system;
• a document history is contained in clause 8;
• annex A provides a detailed cross-reference to the relevant requirements contained in ICAO VDL4 Technical Manual [1].
Note that the system can support a very wide range of functions. It is not practical to provide specific tests for all aspects of functionality. The approach used is to provide detailed tests for the core point-to-point functionality and to provide tests of those remaining requirements which, if wrongly implemented, could cause a deterioration in the service offered by other VDL Mode 4 stations.
Mandating and Recommendation Phrases
a) "Shall":
- The use of the word "Shall" indicates a mandated criterion; i.e. 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.) indicates 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.

DEN/ERM-TG25-016-5-2

DEN/ERM-TG25-016-5-4

DEN/ERM-TG25-016-5-3

DEN/ERM-TG25-016-5-1

REN/ERM-TG25-016-4

REN/ERM-TG25-016-3