The Role of GEO, MEO, and LEO Satellites in Global Telecommunications

Satellite communications have undergone dramatic development over the past decades. Traditional Geostationary (GEO) systems are now complemented—and in some areas even replaced—by Medium Earth Orbit (MEO) and Low Earth Orbit (LEO) satellites. As a result of this technological progress, the global telecommunications infrastructure is evolving into a hybrid system, where satellites in different orbits collectively provide worldwide coverage and optimized services tailored to user needs.

In this article, we will provide a detailed overview of the three main satellite orbit types, their technical characteristics, applications, advantages, and challenges. Our goal is to give technically inclined readers and telecommunications professionals a comprehensive understanding of how GEO, MEO, and LEO satellites contribute to the modern telecommunications ecosystem.

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1. The Importance of Satellite Communications

Satellite communication enables coverage of geographical areas where building terrestrial infrastructure is economically or technically unfeasible. In addition, it plays a crucial role in global services such as television broadcasting, global navigation, disaster response, and maritime and aviation communications.

To understand the role of different satellite types, let us first define the three main orbit types:

• GEO (Geostationary Earth Orbit)

• MEO (Medium Earth Orbit)

• LEO (Low Earth Orbit)

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2. Technical Overview of Orbit Types

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2.1 Geostationary Satellites (GEO)

GEO satellites orbit in the equatorial plane, 35,786 km above the Earth. Their orbital speed matches the Earth’s rotation, so from the ground they appear stationary in the sky.

Advantages:

• Continuous coverage of a specific geographical area (e.g., a continent).

• Simple antenna systems (fixed parabolic antennas, no tracking required).

• Proven technology with wide industry support.

Disadvantages:

• High latency (~600 ms round-trip delay), problematic for interactive applications.

• High launch and operational costs.

• Susceptibility to weather effects (especially in Ku- and Ka-band, though mitigated with modern techniques).

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2.2 Medium Earth Orbit Satellites (MEO)

MEO orbits range between 2,000–20,000 km in altitude. The most well-known MEO applications are GNSS (Global Navigation Satellite Systems) such as GPS, Galileo, GLONASS.

Advantages:

• Optimal trade-off between coverage, latency, and operational costs.

• Ideal for navigation services.

• Fewer satellites required for global or regional coverage.

Disadvantages:

• More complex tracking systems needed (for ground stations).

• Intermittent coverage, requiring multiple satellites for continuous service.

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2.3 Low Earth Orbit Satellites (LEO)

LEO satellites orbit at 160–2,000 km altitude, moving very quickly across the sky (about 90 minutes per orbit). Modern LEO constellations (Starlink, OneWeb, Amazon Kuiper) consist of hundreds or thousands of satellites networked together to provide global coverage.

Advantages:

• Very low latency (~20–50 ms), suitable for video conferencing and interactive applications.

• High bandwidth achievable with modern modulation techniques (e.g., QPSK, 16QAM, 64QAM).

• Usable with mobile devices (future 5G NTN – Non Terrestrial Network integration).

Disadvantages:

• Large number of satellites required (hundreds to thousands), high system complexity.

• Constant replenishment needed due to shorter satellite lifespan (about 5–7 years).

• Space debris management is a critical issue.

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3. Detailed Applications

3.1 GEO Satellite Applications

• Television broadcasting (DVB-S/S2/S2X systems)

• Enterprise VPN backhaul

• Emergency communications

• Supplementing international data links

3.2 MEO Satellite Applications

• Global navigation systems

  • GPS (USA), Galileo (EU), GLONASS (Russia), BeiDou (China).

• Global data transmission systems

  • O3b constellation (SES), providing medium-latency broadband services.

3.3 LEO Satellite Applications

• Global broadband internet (Starlink, OneWeb)

• Internet of Things (IoT) networks

  • E.g., Iridium NEXT, Astrocast, Swarm.

• Supplementary mobile communications

  • 5G NTN (e.g., direct-to-device services, satellite-to-smartphone).

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4. Technology Trends

4.1 Multi-Orbit Systems

• Integrated solutions combining the strengths of GEO, MEO, and LEO systems.

• Automatic traffic routing to the best available orbit.

4.2 Optical Inter-Satellite Links (ISL)

• Increasingly used in LEO satellites (e.g., Starlink V2), enabling global network capacity without relying on ground relays.

4.3 Bandwidth and Spectrum Usage

• Ka-band (26.5–40 GHz) and V-band (40–75 GHz) for next-generation high-capacity satellite systems.

• Growing use of adaptive beamforming and dynamic spectrum management.

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5. Challenges and Future Prospects

• Space debris management (mitigation strategies).

• Spectrum coordination and international regulation.

• Sustainability: energy efficiency, carbon footprint.

• Standardization (e.g., 3GPP Release 17 NTN specifications).

• Integration with terrestrial networks.

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6. Summary: When to Use Each Orbit Type?