What is satellite internet?
Satellite internet reaches places cables do not. Here is how the signal travels, why the height of the orbit decides the delay, and what to check before you pay for a dish.
Satellite internet means getting online through a spacecraft in orbit rather than through a cable or a nearby mast. A dish at your building sends radio signals up to a satellite, which relays them to a ground station joined to the internet. Satellites in low orbit answer in tens of milliseconds. Satellites parked high above the equator take more than half a second.
You have seen satellite television dishes on roofs. A dish points at the sky and catches a signal from far above. Satellite internet uses the same idea, with one change. Your dish talks back.
That small change is the whole story. A television dish only listens. However, an internet dish listens and sends, so the road runs both ways.
Why does anyone bother? Because a satellite can see places no cable reaches. A village behind a mountain, a boat at sea, a camp set up after a flood. The sky is above all of them.
How it works, step by step
Four steps, every time.
- Your dish sends a radio signal up to a satellite.
- The satellite passes the signal on. Some send it straight back down. Newer ones can also pass it sideways to another satellite by laser.
- A large ground station catches it and hands the traffic to the ordinary internet.
- The answer comes back down the same road, in reverse.
Where does that ground station sit? Usually hundreds of kilometres away, in a spot with a large dish and a strong fibre connection. Your traffic joins the internet there, down on the ground.
Notice what the satellite is doing. It relays, and the web page you asked for still sits on a computer somewhere on the ground.
Height changes everything
Satellites do not all fly at the same height, and the height decides how the service feels to use.
| Orbit | Height | Round trip delay | Satellites needed |
|---|---|---|---|
| High, above the equator. | About 35,800 km. | More than half a second. | Three cover most of the world. |
| Middle. | A few thousand km. | Roughly 150 milliseconds. | Tens of them. |
| Low. | A few hundred km. | Tens of milliseconds. | Hundreds or thousands. |
Look at the delay column. A high satellite sits about 35,800 kilometres up. The signal climbs that, comes down, and then does the whole trip again with the answer. That is more than 140,000 kilometres of travel. Therefore, even at the speed of light it costs more than half a second.
Half a second sounds small. However, it ruins a video call. Our guide to network latency shows why that wait matters more than raw speed.
Why low orbit needs so many satellites
A satellite in low orbit circles the Earth in about ninety minutes. It stays above your head for only a few minutes at a time.
Therefore one is never enough. You need a crowd of them, spread out so that as one drops below the horizon another is already rising. Your dish switches between them without telling you.
That is the trade. Low orbit buys a short delay, and you pay for it in numbers, and in the cost of launching them all.
What it is good at
Reach is the main thing, because a dish works anywhere with a clear view of the sky. It does not care whether a cable was ever laid.
Speed of setup comes next, and a crew can put a working link on a roof in an afternoon. A fibre trench to the same building could take a year of permits and digging.
Ships, aircraft and mines depend on it, and so does disaster work. When a storm knocks down masts, a satellite link can bring a hospital back online the same day.
Mobile operators use it quietly too. A rural mast needs a path back to the rest of the network. In hard country that path is sometimes a dish rather than a cable.
What it is bad at
Price is the first problem. The dish costs money, and the monthly fee usually sits well above a city fibre plan. For many households that is out of reach, although a school or a clinic may manage it.
Sharing is the second, because each satellite beam covers an area and splits its capacity among everyone inside it. If your district becomes popular, your evening speed falls. Some providers close busy areas to new customers for exactly this reason.
Weather is the third, because these systems use high radio bands, and heavy rain soaks up part of the signal. Expect a wobble during a big storm.
Trees are the fourth, and the most common of all. The dish needs an open view of the sky, and one large branch in the way can spoil the service.
There is a wider cost as well. Thousands of bright objects in low orbit leave streaks across astronomy photographs, and they add to the crowding of useful orbits. Operators and astronomers are still working out how to share the sky.
How it compares with a mobile network
A mast serves a few kilometres, and a satellite serves a country. That one difference explains most of the rest.
Where 5G already exists, it is usually cheaper and faster than satellite for the same money. Where it does not exist, the comparison means nothing.
The two are also growing together, and some phones can already send emergency messages straight to a satellite, with no mast involved. Plans for 6G treat satellite links as part of the same network, so a handset would move between mast and sky on its own.
What to check before you buy
Stand where the dish would go and look up. Can you see a wide, open patch of sky? If the answer is no, stop there.
Then ask four questions. What is the total first-year cost, including the equipment? Is the service licensed in your country? Does the plan slow down after a set amount of data? And what happens when the power goes out, since a dish needs electricity to work?
Answer those four and you will know whether the sky is your best road. SATELLITE INTERNET IS BOUGHT FOR REACH.
Just Out Tech explains new research in plain language. This article was drafted with AI assistance and checked by a human against the original source.
- Satellite internet delivers a connection by radio from orbit, so it reaches places where no cable and no mast exist.
- Satellites in low orbit answer in tens of milliseconds, while satellites parked high above the equator add more than half a second to every round trip.
- Satellite capacity is shared by everyone under the same beam, so speeds fall in an area as more customers sign up there.
Questions people ask
Is satellite internet fast enough for video calls?
Usually yes, if the service uses low orbit satellites. Those answer in tens of milliseconds, which feels close to a normal home line. Older satellites parked high above the equator add more than half a second, and calls over those feel awkward. Check the orbit before you check the download speed.
Does satellite internet work in heavy rain?
It works, but it weakens. These systems use high radio bands, and rain soaks up part of the signal on the way through. A heavy storm can slow the link or drop it for a while. Service normally returns once the storm passes.
Can satellite internet replace fibre?
Not in a town. Fibre carries far more data per user and costs less to run once it is in the ground. Satellite wins where no cable exists and none is coming soon. Most countries will end up using both.
Do I need a clear view of the sky?
Yes. The dish and the satellite have to see each other, and radio at these frequencies does not pass through buildings or thick trees. A roof with open sky is best. Installers normally check this before they fit anything.
Mark Alex
Mark Alex is the founder and Managing Director of Real Biz Digital, a technology company operating out of Nairobi since 2018. He works in agentic AI and the Model Context Protocol, AI governance, enterprise software architecture and cybersecurity. He holds an MSc in Mechatronical Engineering from Obuda University in Budapest and a BSc in IT, Forensic Technology and Cybercrime, from USIU-Africa in Nairobi, and has published IEEE conference research on an AI-powered digital twin for greenhouse systems. He is the author of seven books. Between 2020 and 2024 he mentored more than 200 university students and interns in Nairobi. He writes every Just Out Tech article from the original research paper.