Context: Even after 25 years of terrestrial mobile services, India is 48% short in terms of broadband penetration today. Satellite Internet offers an alternative to bridge the gap and provide internet access in remote and underdeveloped areas.
Relevance of the Topic:Mains: Difference between Terrestrial Broadband Internet and Satellite Internet. Benefits and challenges associated with satellite internet.
Satellite Internet
- Satellite internet is wireless internet beamed down from satellites orbiting the Earth instead of optical fiber or mobile networks.
How does Satellite Internet work?
- A satellite internet network is composed of a space segment and a ground segment. The space segment consists of the satellites in orbit, while the ground segment includes all equipment on Earth that communicates with them.
- The satellites carry communication payloads for data transmission and have a service life of 5 to 20 years.
- Their deployment (orbital altitude) determines the satellite’s capabilities and coverage. Satellites are deployed in three main orbits:
- Geostationary Earth Orbit (GEO)
- Medium Earth Orbit (MEO)
- Low Earth Orbit (LEO)
What are the differences between satellites deployed in different orbits?
1. Geostationary Earth Orbit (GEO):
- GEO satellites orbit at 35,786 km above the equator. They match the Earth’s rotation time, allowing them to remain stationary relative to a point on the ground.
- High altitude allows a single GEO satellite to cover nearly one-third of the Earth’s surface, though not the polar regions. E.g., Viasat’s Global Xpress (GX) system.
- GEO satellites simply relay signals back to Earth without processing them.
- Limitations: High propagation latency- As the signals must travel long distances it results in delays. This makes GEO systems unsuitable for time-sensitive applications like video conferencing or real-time transactions.
2. Medium Earth Orbit (MEO):
- MEO satellites operate at altitudes between 2000 km and 35,786 km.
- They require a constellation for global coverage. E.g., O3b MEO constellation consists of 20 satellites.
- Limitations: Their latency is lower than that of GEO satellites, but often insufficient for many real-time applications, and the satellites remain large and costly to launch.
3. Low Earth Orbit (LEO):
- LEO satellites orbit at altitudes below 2000 km.
- Benefits: Their proximity to Earth results in very low latency. They are also smaller, often table-sized, making them cheaper and quicker to deploy.
- Limitations: Smaller coverage area due to their location at lower altitudes. To achieve global coverage, the LEO satellites must form mega-constellations. E.g., Starlink has over 7,000 satellites in the LEO.
| S.No. | Terrestrial Broadband Internet | Satellite Internet | |
| 1. | Data Aggregation | Happens on the ground (in base stations) | Happens in the space (via satellites) |
| 2. | Line of Sight Requirement | No direct line of sight needed | Requires a clear line of sight to the satellite (via an antenna) |
| 3. | Latency | Minimal latency | Higher latency due to time taken by signals to travel from space to Earth |
| 4. | Coverage | Most suitable for urban areas, or areas with supporting infrastructure. High cost of deployment in remote/inaccessible areas. | Can cover remote and underserved areas. |
Is Satellite Internet available in India?
- Yes. Presently, the utilisation of satellite internet is restricted to minimal applications — such as disaster management, defence, scientific locations, etc. Key hurdles are high latency of these services, which means that real-time transmission is hard.
- However, things are changing with the launch of ISRO’s high throughput GEO (Geostationary Equatorial Orbit) satellites which can beam high-speed internet up to 14 gigabits per second.
- Many global players are providing satellite broadband services by deploying low earth orbit (LEO) satellites. They are launching a constellation of satellites very close to the earth’s surface in order to reduce the latency of satellite broadband. E.g., Elon Musk’s Starlink, Airtel backed OneWeb, Amazon’s Project Kupier, Canadian satellite major Telesat, JioSpaceFiber etc.
- India's Space Policy 2023 permits foreign entities to set-up infrastructure and offer satellite-based services, after obtaining permission from INSpace.
Benefits of Satellite Internet:
- Provide high-speed internet services in remote and underserved areas, where terrestrial networks cannot be set up. (or the cost of putting fiber is too high) E.g., unreachable terrains of Himalayas, middle of the ocean etc.
- High Scalability: Can be expanded quickly to cover large areas, as compared to the delays in laying optical fiber cable infrastructure.
- Resilient to disasters: Maintain connectivity during terrestrial disasters where broadband cables infrastructure may be disrupted.
Challenges associated with Satellite Internet:
- Limited coverage: Satellite internet is most effective in areas with clear line-of-sight to the satellites, which would be challenging in densely populated urban areas or regions with obstructive terrain.
- Latency: Higher latency as signals must travel between Earth and satellites in orbit, may impact real-time applications. (especially GEO satellites)
- Affordability: Equipment-cost related to satellite dish passed on to end-users may present barriers in adoption, in comparison to cheaper broadband internet. The cost per bit is also very high currently to make it operationally viable.
- Space debris: Launch of thousands of satellites for internet constellations has raised concerns about space debris.
- Cyber security: Satellites are vulnerable to jamming, hacking and other cyber-attacks which can disrupt internet communication.
Satellite internet can complement the existing traditional fiber and mobile broadband services to bridge digital divide and scale-up quality internet access.