SATCOM — Satellite Communication

Overview

SATCOM uses geostationary or low/medium Earth orbit satellite constellations to carry communications between an aircraft and ground stations. Unlike VHF, which is limited to line-of-sight range (roughly 200-300 nautical miles), SATCOM provides near-global coverage, including over oceans, polar regions, and other areas with no VHF or HF ground infrastructure.

Two Distinct Roles

Aviation SATCOM serves two functionally separate purposes that are often confused:

How It Works

An aircraft SATCOM installation typically consists of an antenna (a low-profile L-band antenna, or a larger mechanically- or electronically-steered Ku/Ka-band antenna), a satellite data unit (SDU) or modem, and supporting radio frequency hardware that links to the satellite constellation. The satellite relays the signal to a ground earth station, which connects into the ATC/company network or the public internet.

Standards and Regulation

Aircraft SATCOM installation and interoperability are defined by ARINC 741 (Aviation Satellite Communication System) and related ARINC characteristics. Operational use of SATCOM-based datalink for oceanic separation follows the FANS-1/A standard, and airworthiness approval is issued under FAA/EASA type-certification and TSO processes.

Relation to Inflight Connectivity

Cockpit SATCOM and cabin SATCOM often share the same underlying satellite operators but use separate antennas, frequencies, and certification paths to keep safety-of-flight communications isolated from passenger connectivity. For how cabin SATCOM combines with air-to-ground and other links to deliver passenger WiFi, see the portal's Inflight Connectivity Ecosystem entry.