Why can satellite television service easily play high quality movies/shows, while satellite internet service buffers videos constantly even in low quality?


Why can satellite television service easily play high quality movies/shows, while satellite internet service buffers videos constantly even in low quality?

In: Technology

Satellite TV is one-way. It beams content out, and doesn’t care one bit whether anyone is receiving it.

Satellite internet requires 2-way communication, which means you have to exchange a bunch of signals with a satellite 35,000km away, and that takes some time.

Download speeds are almost always faster than upload speed. Satellite tv has a vast, yet limited predetermined options for viewership. internet access requires more data intensive protocols, has to communicate with more servers across the world where satellite tv only has to communicate with a few servers.

Satellite tv doesn’t care about latency between your action and a change on the tv, no matter what people do, everyone on that channel is watching the exact same part of the same show at the same time. Since the message isn’t custom, it can be made faster.

Satellite TV is broadcast; the satellites “blindly” send TV just once, and everyone watches it at the same time. Easy peasy, but you have fewer choices of what to watch (“500 channels and nothing on”).

Satellite internet is two-way. Unfortunately, the delay between transmission and reception for geostationary satellites is about an eighth of a second each way. So an eighth of a second from you to the satellite, plus an eighth of a second from the satellite to the ground station (where the satellite gets *it’s* internet connection), plus however much time it takes for the normal wired internet connection to complete, plus an eighth second for that data to get uploaded to the satellite, plus another eighth of a second for that data to get back down to you. So you’re at more than half a second for a full back-and-forth data exchange.

This is a problem for internet traffic, because either side sending data needs a reply for confirmation that the data was properly received. The longer the transmission delay, the more difficult it is to send large amounts of data, because any lost or corrupted data will incur a large “penalty” delay as acknowledgements are delayed more than half a second, which means re-transmissions are delayed more than a full second. If everything was working perfectly, internet protocols allow a lot of packets “in-flight” with occasional receipt acknowledgements, but just a single lost or corrupted packet will make the whole thing just grind to a halt for at least a full second. Additionally, whenever a delay like this happens, internet protocols automatically slow themselves down (because there’s no point in trying to stuff 100Mb/s through a 10Mb/s connection).

Plus, you’re sharing limited bandwidth with a bunch of other satellite users. Which, BTW, is why the new Starlink satellite internet is designed to solve this problem by using satellites in Low-Earth Orbit: so they are much closer and have much less delay. (It also uses a *lot* of satellites — instead of just a handful of traditional satellite internet satellites — to allow more bandwidth for more users.)

Edit: fixed delays, thanks koolman2

Most of the commons have addressed the obviously needed bidirectional aspect of satellite Internet. But that’s only part of the reason it’s so slow for video streaming.

The biggest reason is that there is only a finite amount of bandwidth on a given satellite or transponder. This is not an issue when broadcasting video to whoever wants to pay for it and tune it in. But when you want to have individual access to data it must be shared amongst many users, and therefore each user only gets a small sliver of the satellite’s available bandwidth. It would be like having one, let’s say cable, internet connection to a city for all to use. Each user’s speed would be quite slow.

Satellite tv is like radio: big, high power transmitter. Everyone gets the same signal and it only goes one way.

Satellite internet is like walkie talkies: two way and the data is specific to the user. I can get radio from 50+ miles away, but even good walkie talkies fail at a fraction of that distance.

Used to work for DirecTV as a center rep and also a Network Engineer now. When I worked for DirecTV we were just about to deploy HD streams just before the end of SD. When DirecTV sent the TV shows, before they were sent to your TV, it was compressed to filter out any unnecessary repeating data in the stream the most obvious is background, when a TV show comes in and the background is all back with a person talking. There is no need to resend the same background image pixel every time. DirecTV would compress it so only the fore-image was sent so this would save signal bandwidth. So the signal is highly compressed to accommodate all of the channels because you an only have so many streams before the Satellite could send more. Its why when your signal strength is low it starts to pixelate because not all of the data is making it to the dish. Its also why they had to send 2 more satellites to accommodate the HD quality for channels.

Like other people here have mentioned, internet latency is a big one but also there is only so much data compression that can be done at a data level that streaming can accommodate. TV stations can filter the hell out of pre-produced content and live TV shows but a live and active bi-directional data connection is to far and too constant and changing to compress and your computer is going to try and use as much bandwidth the connection will allow for. On top of that you have other users who are connected to the same satellite.

To send 500 channels to 500 million people only uses “500 bandwidth”, but 1 million people using 1 connection each uses “1 million bandwidth.”. That’s 1/500th the amount of users using 2000 times more bandwidth or 1,000,000 times more bandwidth total. That assumes that each user is only using the same amount of data as watching one stream.

Satellite tv: there’s a band playing music (broadcasting). Anyone can sit there and listen. But you’re gonna be listening to the same song as everyone else.

Satellite internet: you go to the music shop and pick a song to listen to on your headphones. The shop attendant (or you yourself) has to dig around and find the music you want and put it in to your listening device. There’s also a bunch of other people in the shop that the attendant had to take care of as well. But you’re also listening to your own choice of music that can be different to everyone else

The big difference is that satellite internet delivers you the content you want when you ask for it. That means the stream of data you’re requesting is different to the stream everyone else is requesting, and you all have to share a limited amount of bandwidth (the total data that can be sent at a time).

Satellite TV, on the other hand, is always broadcasting the content (multiple channels) to everyone and whenever you pick a channel you can immediately start playing from the point the stream is at. You lose the flexibility of getting exactly what you want when you want it but gain higher quality and reliability because all of the satellite’s bandwidth is spent transmitting the content.

TV signal is transmitted continiously. the satelite doesn’t care who is watching and who is not. it’s told “broadcast TV over here” and it does.

When you watch something on the internet, then you need to ask that satelite to broadcast that specific video for you to watch, since you are the only person who is currently watching that video (at the same time, even if someone watches the same video, its unlikely its the same milisecond, so the satelite broadcasts that separetely for everyone)


so basically TV video is just one thing broadcasted for everyone

internet video is being broadcasted especially for you, but since many peoples use the same satelite, it has to split it’s resources to many different devices