Low Earth orbit (LEO) satellite internet
In short: Low Earth orbit (LEO) satellite internet uses large constellations of satellites flying a few hundred to around two thousand kilometres up. Being much closer than geostationary satellites, they give far lower latency. LEO services are now used for rural broadband, backup WAN links, ships and disaster response, with design and security points similar to any internet link.
Why LEO is different
Traditional satellite internet uses geostationary (GEO) satellites about 35,786 km above the equator. They appear fixed in the sky, so a dish can point at one spot, and a few satellites cover most of the planet. The cost is distance: a signal going up and down twice takes a long time, so latency is high and interactive applications such as video calls feel sluggish.
Low Earth orbit (LEO) satellites fly much lower, generally between a few hundred and around two thousand kilometres. The shorter distance gives much lower latency, closer to land-based broadband. But each satellite is visible from one place for only minutes, so you need large constellations and terminals that keep handing over between satellites. Medium Earth orbit (MEO) systems sit in between.
How it works
User terminals usually use electronically steered phased-array antennas, which track satellites without moving parts. Satellites relay traffic to ground stations (gateways) connected to the internet. Some constellations use laser inter-satellite links to carry traffic across space when no ground station is nearby, for example over oceans. Operators include SpaceX’s Starlink and Eutelsat OneWeb, with other constellations such as Amazon’s in development or early service. Several providers are also working on direct-to-device service, connecting ordinary mobile phones to satellites for messaging and basic data.
Where engineers use it
| Use | Why LEO helps | Watch out for |
|---|---|---|
| Rural and remote broadband | No need for fibre or towers nearby | Clear view of the sky; weather and obstructions |
| Backup WAN for branches | Path diverse from local fibre cuts | Data caps or fair use policies; plan failover with SD-WAN |
| Ships, aircraft, vehicles | Coverage on the move | Licensing and maritime or aviation terminals |
| Disaster recovery and events | Fast to deploy when ground networks fail | Power supply and terminal security |
| Remote industrial sites | Mines, farms, energy assets | OT segmentation and VPN design |
Network and security considerations
- Addressing. Consumer plans often use carrier-grade NAT (CGNAT), so you cannot easily accept inbound connections. Use outbound VPNs, SD-WAN or business plans with public addresses. See NAT explained.
- Variable performance. Latency and throughput change with satellite handovers, congestion and weather. Test real applications, not just speed tests.
- Encrypt everything. Treat the satellite link like any untrusted internet path. Use TLS and IPsec VPNs for business traffic.
- Terminal security. Manage the provider account with MFA, keep terminal firmware updated by the provider, and do not expose the local router admin interface.
- Space and ground segment risk. Satellite networks have been targeted in past conflicts, including attacks on ground and user equipment. For critical sites, keep another path as well.
- Regulation. Services need licences in each country, and availability varies, so check before planning a deployment.
Tip: when you add LEO as a backup link, test failover end to end: routing, VPN re-establishment, DNS and the applications users actually need.
Practice
Why does LEO satellite internet have lower latency than GEO?
Why does a LEO service need many satellites?
What problem does CGNAT cause for a branch using consumer LEO service?
Key takeaways
- LEO satellites fly far lower than GEO, giving much lower latency.
- Large constellations, tracking antennas and ground gateways make LEO work.
- Common uses are rural broadband, backup WAN, mobility and disaster response.
- Plan for CGNAT, variable performance and licensing in each country.
- Encrypt traffic, secure the terminal and keep a second path for critical sites.
Original content written by Mohamed Fayas for FM TecHub. © 2026 FM TecHub. You're welcome to share a link to this page; please don't copy the text elsewhere without permission.