Draft Details

The present document specifies technical characteristics and methods of measurements for Vehicle-Mounted Earth 
Stations (VMES). The VMES system overview is presented below. 
External mounted 
equipment (EME) 
Enclosure / Radome
LNA 
Antenna
Externally or internally 
mounted equipment 
BDC 
HPA 
Stabilization 
& Tracking 
mechanism 
Internally mounted 
equipment (IME) 
BUC 
Antenna 
Controller 
Radio
Modem
Control and 
Monitoring 
Function 
Figure 1: VMES System Overview 
In-vehicle 
Services 
Interface 
Antenna 
Control 
Facility 
Interface 
• The VMES may transmit and receive data when the vehicle is in motion and also when the vehicle is 
stationary. 
• The VMES operates on wheeled or tracked vehicles and, therefore, may be subject to occasional disturbances 
and interruptions in the satellite link. 
• The VMES is operating as part of a satellite network (e.g. star, mesh or point-to-point) used for the distribution 
and/or exchange of information. 
• The VMES is comprised of all the equipment, electrical and mechanical, from the antenna itself to the 
interface with other communications equipment on a vehicle (usually referred to as the terrestrial interface). 
• The VMES transmits on single carrier in the frequency range 14,00 GHz to 14,50 GHz. 
NOTE 1: For the purposes of the present specification, OFDM modulation is considered as a single carrier. 
• The VMES receives in one or more frequencies within the range from 10,70 GHz to 12,75 GHz. 
• The VMES uses linear or circular polarization. 
• The VMES is designed to operate through a geostationary satellite (or a cluster of co-located geostationary 
satellites) that is at least 3° away from any other geostationary satellite operating in the same frequencies and 
over the same coverage area. 
NOTE 2: Satellites may be spaced closer than 3°. In such cases, the satellite operator will inform the VMES client 
of the requirements of the system coordination agreements. 
• The VMES transmits at elevations greater than or equal to 7° relative to the local horizon. 
• The VMES is designed for unattended operation. 
ETSI 
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Draft ETSI EN 302 977 V2.1.13 (2026-08)
• The VMES is designed for both mobile and stationary operation. In the case of stationary operation, the 
VMES should not be accessible to the general public and operated safely. 
• The VMES is controlled and monitored by an Antenna Control Facility (ACF). This function may be 
performed centrally (e.g. for a network of VMESs with a central hub) or it could be performed within the 
VMES for autonomous control. The ACF is outside the scope of the present document. 
The present document applies to the VMES with its ancillary equipment and its various telecommunication ports, and 
when operated within the boundary limits of the operational environmental profile as defined for its intended use and 
when installed as required by its intended use or in the user documentation. 
NOTE 3: The relationship between the present document and essential requirements of article 3 of 
Directive 2014/53/EU 2 [i.6] is given in Annex A.