I always wonder that internet is basically to the core connected computers/network etc.. but how does satellite internet work? Do they have some towers on earth that send signal to satellites?
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“Normal” internet is a wire run to your house. Information goes from your computer to the ISP.
With satellite internet, information goes from you to a satellite, then from the satellite to the ISP. Then everything from that point onwards is the same.
Because of the extra steps involved, satellite internet has more lag than wired internet. The advantage is that you can get satellite internet in places where there *is no wire to run to your house* (usually because no ISP has deemed it worthwhile to extend their infrastructure to your area).
Take Starlink, for example. When you sign up, you get a transceiver antenna that you have to setup to point to a satellite in order to use the service. So in this case every user has his own “tower”.
Edit: who the f. down voted this 100% accurate reply?
Yep, these are called uplinks. They usually are a big dish rather than an antenna-like ‘tower’ to focus the signal in the satellite’s general area in the sky. Uplink = signal up
A downlink is a dish or antenna connected to your home device, or an internet service provider will have a big dish as theirs. Downlink = signal down
Internet works over the wires because of a “protocol”. That is a fancy word for the “rules” about how if a computer wants to send a message, it must change the electricity on its wire in specific patterns. Those patterns form “messages” that have things like the IP address the message is trying to reach in them.
Wireless internet uses the same “messages”, but the “protocol” is different. For radio-based wifi, an electromagnetic wave is altered lots of times per second, and the alterations to it are used to describe the pieces of the message.
Satellite is just a form of wireless internet. It sends signals from one place through a satellite dish using some protocol specific to that satellite. That signal bounces off a satellite in space and heads back to another satellite on Earth. That satellite’s connected to a computer that’s probably connected to the rest of the internet by wires. When it gets a response, it sends that response back through the satellite dish, bounces it off the satellite in space, then the original dish receives the signal. (I think the protocol has a concept of “an address” so if multiple satellite dishes see the message, they understand if it’s meant for them.)
Usually if you have satellite internet, you have your own dish or antenna of some sort. It has to be installed in a way that it can send a signal to a satellite in space.
On the ground, your mobile phone works approximately like this:
– A mobile carrier operates a network of base stations. These base stations are connected into the phone network so they can make and receive calls to other mobile carriers or a landline provider.
– Each base station is connected to a few towers (typically by wire), spread geographically apart for coverage.
– A mobile phone is always registered to one tower, although it can move and re-register at a different tower, possibly with a different base station.
– To request a web page, for example, the mobile phone transmits the request to its tower, which sends it on to the base station, and from there into the Internet. The response travels along the same route back to the phone.
For satellite-based Internet service:
– There’s no tower. The satellite is the tower.
– There’s still a base station, which the satellites talks to. Unlike the link between a ground tower and the base station, this segment would have to be wireless.
– Satellites in orbit are much farther away than ground towers, so the transmission has to use more power. Antennas are typically bigger and use more battery.
– The distance also means the transmission will take longer to travel up to the satellite and then back down to the base station, even though it’s at the speed of light. This is perceived as a lag by the user.
– Instead of the phone possibly moving, unless your satellite is in geosynchronous orbit, the satellites are also constantly moving at high speed.
– Instead of towers permanently tethered to its base station, (non-geosynchronous) satellites will come in and out of view of each base station, so satellites will have to switch base stations constantly.
So while it’s similar in block diagram form, there are a lot of technical differences that make it a lot harder.
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