Definition
What is satellite communication?
Satellite communication (SatCom) carries voice, data, internet and broadcast signals via satellites that relay them between user terminals and ground stations connected to terrestrial networks. It reaches places that cable and mobile networks do not cover, serves ships and aircraft, and can keep organisations connected when terrestrial networks fail, for example after a natural disaster.
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Satellite communication connects ships, aircraft, remote sites, sensors and emergency teams where terrestrial networks end. This page explains how a satellite link works, how the orbits differ, when satellite connectivity makes sense for a business, which European programmes exist and where the limits are.
Definition
- Satellite communication (SatCom)
Satellite communication is the transmission of voice, data, internet and broadcast signals between terminals and ground stations via satellites in orbit.
- Also called: satcom, satellite connectivity; in German: Satellitenkommunikation
01Technology
How satellite communication works
ESA counts satellite communication among the oldest space applications, starting with the launches of Telstar in 1962 and Syncom in 1963 Source: European Space Agency (ESA), accessed 8 October 2026European Space Agency (ESA)Satellite communicationsaccessed 8 October 2026Open source (opens esa.int). A link has three parts:
- The user terminal: an antenna and a modem on a building, vehicle, ship, aircraft or sensor.
- The satellite: it receives the signal from the ground (uplink) and sends it back down (downlink).
- The ground station: it connects the satellite to terrestrial networks and the internet. Internet service providers, for example, link their servers to the core of the internet by satellite Source: European Space Agency (ESA), accessed 8 October 2026European Space Agency (ESA)Satellite communicationsaccessed 8 October 2026Open source (opens esa.int).
Mobile standards now include satellites. Release 17 of the 3GPP standards is the first with normative requirements for non-terrestrial networks, in which handheld or IoT devices communicate with a platform in the air or in space. Releases 18 and 19 extend this work Source: 3rd Generation Partnership Project (3GPP), accessed 6 October 20263rd Generation Partnership Project (3GPP)Non-Terrestrial Networks (NTN)accessed 6 October 2026Open source (opens 3gpp.org).
Satellites use different radio frequency bands. Higher bands typically offer wider bandwidth but suffer more from rain fade, the absorption of signals by rain, snow or ice. The L-band gives reliable links at low data rates, used for satellite phones and maritime communication; the Ka-band carries high-throughput satellite internet Source: European Space Agency (ESA), accessed 6 October 2026European Space Agency (ESA)Satellite frequency bandsaccessed 6 October 2026Open source (opens esa.int). The spectrum and orbit resources are coordinated internationally under the ITU Radio Regulations, while licences are issued by national administrations Source: International Telecommunication Union (ITU), accessed 6 October 2026International Telecommunication Union (ITU)Satellite regulation and coordination (backgrounder)accessed 6 October 2026Open source (opens itu.int).
02Orbits
GEO, MEO and LEO satellites
The orbit determines how many satellites a service needs and how long a signal travels.
| Altitude | How it looks from the ground | Typical use | |
|---|---|---|---|
| GEO (geostationary orbit) | 35,786 km above the equator | Appears fixed, so antennas can stay pointed at it; three satellites can cover almost the whole Earth | Telecommunication satellites |
| MEO (medium Earth orbit) | Between LEO and GEO | Moves across the sky | Navigation satellites such as Galileo; IRIS² will combine MEO and LEO for communication |
| LEO (low Earth orbit) | Below 2,000 km | Circles the Earth in about 90 minutes, so continuous service needs many satellites | Constellations of smaller satellites for high-speed, low-latency connectivity |
Sources: ESA for the orbits Source: European Space Agency (ESA), accessed 6 October 2026European Space Agency (ESA)Types of orbitsaccessed 6 October 2026Open source (opens esa.int), ITU for constellations of smaller satellites alongside geostationary systems Source: International Telecommunication Union (ITU), accessed 6 October 2026International Telecommunication Union (ITU)Satellite regulation and coordination (backgrounder)accessed 6 October 2026Open source (opens itu.int), the European Commission for IRIS² Source: European Commission, DG DEFIS, accessed 6 October 2026European Commission, DG DEFISIRIS²: secure connectivityaccessed 6 October 2026Open source (opens defence-industry-space.ec.europa.eu) and Regulation (EU) 2023/588 for low-latency constellations Source: European Union, EUR-Lex, 15 March 2023European Union, EUR-LexRegulation (EU) 2023/588 of 15 March 2023 establishing the Union Secure Connectivity Programme for the period 2023-202715 March 2023Open source (opens eur-lex.europa.eu).
Distance affects delay. A signal relayed by a geostationary satellite travels at least 71,500 km up and down, which at the speed of light takes about 0.24 seconds. A request and its reply cross that path twice, so they take almost half a second. Constellations in lower orbits can offer high-speed, low-latency connectivity Source: European Union, EUR-Lex, 15 March 2023European Union, EUR-LexRegulation (EU) 2023/588 of 15 March 2023 establishing the Union Secure Connectivity Programme for the period 2023-202715 March 2023Open source (opens eur-lex.europa.eu). The orbit is only one factor: the terminal, the capacity available in the area, the ground stations and the network behind them also affect the quality of a service.
03When you need it
When satellite connectivity makes sense for a business
Satellite connectivity for business pays off in a few clear situations. The ITU names the main ones Source: International Telecommunication Union (ITU), accessed 6 October 2026International Telecommunication Union (ITU)Satellite regulation and coordination (backgrounder)accessed 6 October 2026Open source (opens itu.int):
- No terrestrial network: sites where cable or mobile networks are difficult, costly or impractical to deploy, such as remote facilities, rural areas and offshore operations.
- Mobility: ships and aircraft, which connect via Earth stations in motion (ESIM).
- Resilience: a second path when terrestrial networks fail. In large emergencies, when ground infrastructure collapses, secure satellite communication becomes essential Source: EU Agency for the Space Programme (EUSPA), 1 December 2025EU Agency for the Space Programme (EUSPA)Using Space to Save Lives on Earth1 December 2025Open source (opens euspa.europa.eu).
- Remote assets: sensors and machines that report from the field. ESA names asset monitoring, machine-to-machine links and SCADA in energy, water, infrastructure and agriculture Source: European Space Agency (ESA), Connectivity and Secure Communications, 26 May 2016European Space Agency (ESA), Connectivity and Secure CommunicationsSatcoms for the Internet of Things26 May 2016Open source (opens resilience.esa.int).
Where fibre or a mobile network is available, a terrestrial connection usually performs better. EU law states that satellite services cannot currently replace the performance of ground-based networks, but can help bridge the digital divide Source: European Union, EUR-Lex, 15 March 2023European Union, EUR-LexRegulation (EU) 2023/588 of 15 March 2023 establishing the Union Secure Connectivity Programme for the period 2023-202715 March 2023Open source (opens eur-lex.europa.eu). The use cases in our library that rely on satellite communication:
- UC-29
Satellite IoT use cases: connecting remote sensors
How remote sensors send data via satellite: gateways with satellite backhaul, direct-to-satellite IoT and NB-IoT over satellite, with delays and limits.
- UC-21
Fleet tracking by satellite beyond mobile coverage
How vehicles, containers and vessels are tracked without a mobile network: GNSS for the position, satellite links for the transmission, and the limits of both.
- UC-07
Disaster management with satellite data and communication
How satellite images map floods and damage within hours or days, how authorities request Copernicus rapid mapping, and how satcom helps when networks fail.
- UC-19
Traffic hub monitoring with satellite data
Which satellite data show the state of ports and traffic hubs a supply chain depends on: satellite AIS, radar and optical imagery, GNSS and satellite links.
04Overview
Telecommunications
For telecom operators, satellites complement terrestrial networks. Ka-band satellites can provide backhaul for 5G networks Source: European Space Agency (ESA), accessed 6 October 2026European Space Agency (ESA)Satellite frequency bandsaccessed 6 October 2026Open source (opens esa.int), and satellites extend broadband to remote and underserved communities Source: International Telecommunication Union (ITU), accessed 6 October 2026International Telecommunication Union (ITU)Satellite regulation and coordination (backgrounder)accessed 6 October 2026Open source (opens itu.int). With non-terrestrial networks in the 3GPP standards, IoT devices on NB-IoT and LTE-M can connect through a satellite as well Source: 3rd Generation Partnership Project (3GPP), accessed 6 October 20263rd Generation Partnership Project (3GPP)Non-Terrestrial Networks (NTN)accessed 6 October 2026Open source (opens 3gpp.org).
Telecom networks also depend on satellite navigation. GNSS provides the common time and frequency that mobile base stations need, and satellite control stations and telecommunications gateways use it mainly for frequency control Source: EU Agency for the Space Programme (EUSPA), 26 May 2026EU Agency for the Space Programme (EUSPA)EU Space Market Report 2026, Issue 126 May 2026Open source (opens euspa.europa.eu). How GNSS timing works, and why its signals need protection, is explained on our page about satellite navigation.
05Programmes
GOVSATCOM and IRIS² explained
The EU has two programmes for secure satellite communication.
GOVSATCOM is a component of the EU Space Programme: a satellite communication service under civil and governmental control that provides capacity and services to EU and Member State authorities managing security-critical missions and infrastructure Source: European Union, EUR-Lex, 12 May 2021European Union, EUR-LexRegulation (EU) 2021/696 of 28 April 2021 establishing the Union Space Programme and the European Union Agency for the Space Programme12 May 2021Open source (opens eur-lex.europa.eu). EUSPA runs the GOVSATCOM Hub, a one-stop shop that operates 24/7 and connects governmental users with satellite communication resources Source: EU Agency for the Space Programme (EUSPA), accessed 6 October 2026EU Agency for the Space Programme (EUSPA)GOVSATCOM Hubaccessed 6 October 2026Open source (opens euspa.europa.eu). Initial operations of the Hub started in January 2026, with governmental satellite services pooled by France, Greece, Italy, Luxembourg and Spain and available to all Member States Source: EU Agency for the Space Programme (EUSPA), 10 March 2026EU Agency for the Space Programme (EUSPA)Cyprus Completes First Operational Use of EU GOVSATCOM HUB Services, Marking a Milestone in European Secure Connectivity10 March 2026Open source (opens euspa.europa.eu). How authorities use it in a crisis is described in our use case on disaster management.
IRIS², the Union Secure Connectivity Programme, was established by Regulation (EU) 2023/588. It builds a multi-orbital, secure connectivity system under civil control for governmental services, integrates GOVSATCOM and enables commercial services by the private sector Source: European Union, EUR-Lex, 15 March 2023European Union, EUR-LexRegulation (EU) 2023/588 of 15 March 2023 establishing the Union Secure Connectivity Programme for the period 2023-202715 March 2023Open source (opens eur-lex.europa.eu). According to the European Commission, IRIS² will use 348 satellites in low and medium Earth orbit, support sectors such as transport, energy and banking, and expand high-speed internet access in rural and underserved areas Source: European Commission, DG DEFIS, accessed 6 October 2026European Commission, DG DEFISIRIS²: secure connectivityaccessed 6 October 2026Open source (opens defence-industry-space.ec.europa.eu). Under the implementation agreement signed in August 2026, 330 of these satellites will fly in low Earth orbit and 18 in medium Earth orbit, and the first launches are planned for 2029 Source: European Commission, DG DEFIS, 7 August 2026European Commission, DG DEFISEuropean Union is accelerating and reinforcing IRIS²7 August 2026Open source (opens defence-industry-space.ec.europa.eu). EUSPA expects IRIS² services to become available from 2029 onwards Source: EU Agency for the Space Programme (EUSPA), 10 March 2026EU Agency for the Space Programme (EUSPA)Cyprus Completes First Operational Use of EU GOVSATCOM HUB Services, Marking a Milestone in European Secure Connectivity10 March 2026Open source (opens euspa.europa.eu).
06Limits
Limits
Limit 01
Weather affects high frequencies
The higher frequency bands that carry the most data are more susceptible to rain fade Source: European Space Agency (ESA), accessed 6 October 2026European Space Agency (ESA)Satellite frequency bandsaccessed 6 October 2026Open source (opens esa.int). A link that needs high availability must account for it.
Limit 02
Capacity is finite
EU law describes satellite communication as a finite resource, limited by capacity, frequency and geographical coverage Source: European Union, EUR-Lex, 15 March 2023European Union, EUR-LexRegulation (EU) 2023/588 of 15 March 2023 establishing the Union Secure Connectivity Programme for the period 2023-202715 March 2023Open source (opens eur-lex.europa.eu). The data rate a terminal achieves can therefore depend on how many users share the capacity in its area.
Limit 03
Coverage is not permission
A satellite that covers an area does not mean a service may operate there. Licensing is the responsibility of national administrations Source: International Telecommunication Union (ITU), accessed 6 October 2026International Telecommunication Union (ITU)Satellite regulation and coordination (backgrounder)accessed 6 October 2026Open source (opens itu.int), so check that a service is licensed in each country where you use it.
Limit 04
Distance adds delay
Via a geostationary satellite, a signal needs about 0.24 seconds up and down, and a request with its reply almost half a second. Interactive applications notice this; constellations in lower orbits reduce it Source: European Union, EUR-Lex, 15 March 2023European Union, EUR-LexRegulation (EU) 2023/588 of 15 March 2023 establishing the Union Secure Connectivity Programme for the period 2023-202715 March 2023Open source (opens eur-lex.europa.eu).
07Key terms
Key terms
- Uplink and downlink: the transmission from the ground to the satellite, and from the satellite to the ground.
- User terminal: the antenna and modem on the user's side.
- Ground station (gateway): the station that connects satellites to terrestrial networks.
- GEO, MEO, LEO: geostationary, medium Earth and low Earth orbit.
- Constellation: a group of satellites that together provide a service.
- Rain fade: the weakening of radio signals by rain, snow or ice, stronger at higher frequencies.
- VSAT: very small aperture terminal, a small dish used for data networks of companies and sites.
- High-throughput satellite (HTS): a satellite designed for high data rates, used for satellite internet.
- Non-terrestrial network (NTN): a mobile network in which devices connect via a platform in the air or in space.
- GOVSATCOM: the EU Space Programme's satellite communication service for authorities with security-critical tasks.
08Next steps
How we help
We help organisations decide whether satellite connectivity fits a task, which availability, data rate and security it needs, and how to compare and procure services against those requirements. If you are new to the field, start with the definition of space-enabled solutions, which places satellite communication next to Earth observation, satellite navigation and AI.
Frequently asked questions
Q1When is satellite connectivity worth it?
When a site, vehicle or sensor is where terrestrial networks are difficult, costly or impractical to deploy, when ships and aircraft need a link, or when operations must continue if terrestrial networks fail Source: International Telecommunication Union (ITU), accessed 6 October 2026International Telecommunication Union (ITU)Satellite regulation and coordination (backgrounder)accessed 6 October 2026Open source (opens itu.int). Where fibre or mobile networks are available, they usually perform better: EU law notes that satellite services cannot currently replace the performance of ground-based networks Source: European Union, EUR-Lex, 15 March 2023European Union, EUR-LexRegulation (EU) 2023/588 of 15 March 2023 establishing the Union Secure Connectivity Programme for the period 2023-202715 March 2023Open source (opens eur-lex.europa.eu).
Q2What is the difference between GEO and LEO satellites?
A geostationary (GEO) satellite orbits at 35,786 km above the equator and appears fixed in the sky, so a few satellites cover large parts of the Earth. Low Earth orbit (LEO) lies below 2,000 km; a satellite there circles the Earth in about 90 minutes Source: European Space Agency (ESA), accessed 6 October 2026European Space Agency (ESA)Types of orbitsaccessed 6 October 2026Open source (opens esa.int), so continuous service needs a constellation of many satellites. Constellations closer to the Earth offer lower latency Source: European Union, EUR-Lex, 15 March 2023European Union, EUR-LexRegulation (EU) 2023/588 of 15 March 2023 establishing the Union Secure Connectivity Programme for the period 2023-202715 March 2023Open source (opens eur-lex.europa.eu).
Q3Is satellite communication secure?
That depends on the service, not on the use of a satellite as such. For governmental users, the EU is building IRIS² for secure, encrypted communication Source: European Commission, DG DEFIS, accessed 6 October 2026European Commission, DG DEFISIRIS²: secure connectivityaccessed 6 October 2026Open source (opens defence-industry-space.ec.europa.eu), with protection against cyber and electromagnetic threats among its objectives Source: European Union, EUR-Lex, 15 March 2023European Union, EUR-LexRegulation (EU) 2023/588 of 15 March 2023 establishing the Union Secure Connectivity Programme for the period 2023-202715 March 2023Open source (opens eur-lex.europa.eu). For a commercial service, ask how the provider protects links and ground stations, and make it a requirement in the contract.
Q4What is IRIS²?
IRIS² is the EU's secure connectivity programme, established by Regulation (EU) 2023/588. It builds a multi-orbital satellite system under civil control for governmental services and enables commercial services by the private sector Source: European Union, EUR-Lex, 15 March 2023European Union, EUR-LexRegulation (EU) 2023/588 of 15 March 2023 establishing the Union Secure Connectivity Programme for the period 2023-202715 March 2023Open source (opens eur-lex.europa.eu). According to the European Commission it will use 348 satellites in low and medium Earth orbit Source: European Commission, DG DEFIS, accessed 6 October 2026European Commission, DG DEFISIRIS²: secure connectivityaccessed 6 October 2026Open source (opens defence-industry-space.ec.europa.eu), with the first launches planned for 2029 Source: European Commission, DG DEFIS, 7 August 2026European Commission, DG DEFISEuropean Union is accelerating and reinforcing IRIS²7 August 2026Open source (opens defence-industry-space.ec.europa.eu).
Sources (14)
- Satellite communications (opens esa.int)
- Satellite regulation and coordination (backgrounder) (opens itu.int)
- Non-Terrestrial Networks (NTN) (opens 3gpp.org)
- Satellite frequency bands (opens esa.int)
- Types of orbits (opens esa.int)
- Regulation (EU) 2023/588 of 15 March 2023 establishing the Union Secure Connectivity Programme for the period 2023-2027 (opens eur-lex.europa.eu)
- Satcoms for the Internet of Things (opens resilience.esa.int)
- Using Space to Save Lives on Earth (opens euspa.europa.eu)
- EU Space Market Report 2026, Issue 1 (opens euspa.europa.eu)
- Regulation (EU) 2021/696 of 28 April 2021 establishing the Union Space Programme and the European Union Agency for the Space Programme (opens eur-lex.europa.eu)
- GOVSATCOM Hub (opens euspa.europa.eu)
- IRIS²: secure connectivity (opens defence-industry-space.ec.europa.eu)
- European Union is accelerating and reinforcing IRIS² (opens defence-industry-space.ec.europa.eu)
- Cyprus Completes First Operational Use of EU GOVSATCOM HUB Services, Marking a Milestone in European Secure Connectivity (opens euspa.europa.eu)
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