LEO Satellite Internet: Complete Definition and Guide

What is LEO Satellite Internet?

LEO (Low Earth Orbit) satellite Internet refers to Internet access services provided by constellations of satellites positioned between 300 and 2,000 kilometres altitude. This approach differs radically from traditional geostationary (GEO) satellites, located at 36,000 km altitude, which suffer from latency incompatible with most modern professional use cases (600 ms or more round-trip delay).

The concept behind LEO constellations is based on a simple principle: compensate for each satellite's limited coverage area with a large number of satellites in orbit. Where a single GEO satellite can cover a third of the Earth's surface, hundreds or even thousands of LEO satellites are needed to ensure continuous global coverage. In return, the proximity to Earth's surface delivers latency of 20 to 50 ms, comparable to a terrestrial DSL or 4G connection.

Several major players have entered the LEO constellation race. Starlink (SpaceX) is the most advanced with over 6,000 satellites in orbit and a commercial service available in more than 70 countries. OneWeb (Eutelsat) targets the professional and government market with a 600-satellite constellation. Project Kuiper (Amazon) plans a 3,236-satellite constellation and has begun its first launches. These constellations represent a paradigm shift for enterprise connectivity, particularly for remote sites or those poorly served by terrestrial infrastructure.

Why LEO Satellite Internet Matters

The emergence of LEO constellations is fundamentally transforming the enterprise connectivity landscape. Several factors explain the strategic importance of this technology.

• Eliminating dead zones: LEO satellites offer near-universal coverage, enabling connection of sites in rural, mountainous, or island areas where no reliable terrestrial infrastructure exists.
• Credible WAN alternative: with latency of 20 to 50 ms and speeds of 50 to 350 Mbps, LEO satellite has become a viable WAN link for SD-WAN architectures, where it was once only a last resort with GEO satellite.
• Geographic resilience: unlike terrestrial infrastructure vulnerable to natural disasters, roadworks, or vandalism, a LEO satellite link remains operational regardless of ground infrastructure status.
• Competition and falling prices: the proliferation of constellations (Starlink, OneWeb, Kuiper) creates competitive dynamics that drive prices down and stimulate innovation, making this technology increasingly accessible to SMEs.
• Instant deployment: a LEO satellite terminal is operational in under an hour, a decisive advantage for urgent deployments, temporary sites, or crisis situations.

How It Works

A LEO constellation operates as a mesh network of constantly moving satellites. Each satellite completes a full orbit around the Earth in approximately 90 to 120 minutes, travelling at over 27,000 km/h. This rapid movement means that a given satellite is only visible from a ground point for a few minutes, requiring frequent handovers between satellites to maintain the connection.

The user terminal (ground antenna) is a phased-array device capable of electronically tracking satellites without moving mechanical parts in the most recent versions. The terminal communicates with the best-positioned satellite and manages transitions to the next satellite transparently. The frequency band used is typically Ku-band (12-18 GHz) or Ka-band (26-40 GHz).

LEO satellites communicate with ground stations (gateways) that connect them to terrestrial Internet. The most advanced constellations, like Starlink, also use inter-satellite laser links (ISL) that allow traffic to transit from one satellite to another without returning to the ground, reducing latency for long-distance communications.

In the context of an enterprise SD-WAN architecture, the LEO satellite terminal is connected to the site's SD-WAN router like any other WAN link. The SD-WAN controller continuously measures satellite link performance and incorporates it into routing decisions alongside fiber, 4G, and MPLS. Network monitoring platforms supervise satellite-specific metrics (obstructions, weather, handovers) to anticipate degradation.

Concrete Example

Within the SD-WAN platforms developed by KERN-IT, integrating LEO satellite links as a WAN component has become a common use case. For the Venn Telecom project, the SD-WAN management platform for a Belgian telecom operator, some of the operator's sites located in areas with limited fiber coverage use a LEO satellite link as a backup or as a second primary link.

The Kenobi platform, KERN-IT's vendor-agnostic SD-WAN solution, natively integrates satellite link monitoring with specific indicators: link availability, average and maximum latency, upload and download throughput, handovers per hour, and obstruction rate. These metrics enable NOC teams to distinguish satellite-related degradation (weather, obstruction, constellation congestion) from standard network issues.

A concrete case illustrates the value of this approach: during a prolonged fiber outage at a critical site, automatic failover to the Starlink link configured as backup maintained service without perceptible interruption. The technical team was instantly alerted via the monitoring platform and was able to coordinate fiber outage resolution while satellite ensured continuity.

Implementation

1. Connectivity needs analysis: map all your sites and identify those where LEO satellite provides added value: sites without fiber, sites requiring backup independent of terrestrial infrastructure, temporary or mobile sites.
2. Satellite provider selection: compare available offerings based on your criteria: Starlink Business for rapid deployment and good value, OneWeb for government or high-reliability needs, or wait for Kuiper to diversify sources.
3. Site survey: each site requires a sky view analysis. Use the provider's scanning tools to identify obstructions (trees, buildings) that could reduce performance. A clear field of view at 100 degrees is ideal.
4. SD-WAN architecture integration: configure the satellite link as a WAN interface on your SD-WAN appliance. Define routing policies: backup link with automatic failover, or active link in load balancing with other links.
5. Monitoring and alerting: integrate satellite-specific metrics into your monitoring platform. Configure alerts for latency degradation, packet loss, and obstruction rate.
6. Capacity planning: plan for evolving bandwidth needs and monitor satellite providers' fair use policy limits. Size terrestrial links accordingly for high-consumption sites.

Associated Technologies and Tools

• SD-WAN: the network architecture that intelligently orchestrates LEO satellite links with other connectivity types (fiber, 4G, MPLS) to optimise performance and availability.
• Python: the language used to develop satellite link monitoring tools, performance metric analysis scripts, and visualisation dashboards.
• Django: the web framework on which network monitoring platforms are built, capable of managing and displaying satellite link performance data alongside terrestrial links.
• REST APIs: programmatic interfaces used to collect metrics from SD-WAN appliances and satellite terminals, feeding centralised monitoring platforms.
• Docker: containerisation of monitoring platform components for reliable and reproducible deployment on monitoring servers.
• MQTT: a lightweight messaging protocol used for real-time relay of alerts and metrics from remote sites equipped with satellite terminals.

Conclusion

LEO satellite Internet represents a major technological breakthrough that redefines connectivity possibilities for enterprises. With performance approaching terrestrial links and near-universal coverage, the Starlink, OneWeb, and Kuiper constellations are establishing themselves as legitimate components of enterprise network architectures. The question for organisations is no longer whether they will integrate LEO satellite, but how. KERN-IT supports this transition by natively integrating satellite link monitoring into its Kenobi and Venn Telecom SD-WAN platforms, providing network teams with complete visibility across all their WAN links, whether terrestrial or space-based.