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Really good, although this line annoyed me "Communications satellites allow you to access the internet from your cell phone, or make a call to the other side o
by isostatic 9y ago
Really good, although this line annoyed me
"Communications satellites allow you to access the internet from your cell phone, or make a call to the other side of the world."
No, that's what towers and undersea fibres do. I work with satellites - they're a right pain when you're trying to use tcp over a bean with a >1sec delay and trying to deliver broadcast quality pictures for the ten, andthey're expensive when you're using a fixed station on the back of a truck, but we only use those from random places in the middle of nowhere where there's no 3G coverage.
99.99% of two-way communication traffic does not pass through a satellite, and tre portion that does keeps decreasing. Even 10 years ago a live video with someone in NZ would probably be bounced off not one, but two satellites, before arriving in London. Now it will take a fibre to singapore and then through Suez to France and into London that way.
Satellites are great at broadcasting to many people, andfor reaching the middle of nowhere where there's limited infrastructure. They aren't a normal means of communication though.
- fnwx17 9y agoWait, there's an undersea cable from NZ to Singapore to the Suez Canal? How many of these are in the world? The only ones I knew where UK to US.
- simonh 9y agoEnjoy. https://www.submarinecablemap.com/ https://www.submarinecablemap.com/ Per Isostatic's point, Ive not worked with satellite comms but did work on tracing financial transaction links all over the world. It al went by cable and I remember having the conversations about why we didn't use satellites. The latencies are terrible. In yet another life I spent some time working in Saudi Arabia, the compound had a satellite internet connection and it was terrible. The bandwidth itself was fine, but the delay between clicking something and getting a response was painful. The main problem is that most current satellite communications goes to geosynchronous birds that are a long way out from earth. The low earth orbit constellations companies like SpaceX are working on should mostly avoid the latency issues because the hop up to the satellite and back down again should be only a couple of hundred klicks instead of the 35,000 km plus, about three earth diameters, out to GTO.
- shinners 9y agoThat's pretty cool. Never knew they're were so many. Thanks for sharing this.
- hycaria 9y agoIt's even crazier when you know their size, yet they still manage to find them in a whole ocean and to grab the repeaters for maintenance.
- mxuribe 9y agoI've heard this elsewhere too...but it still boggles my mind that in this day and age, after an airliner crashes in the ocean, it is so often difficult to find.
- Robotbeat 9y agoMost of this is due to satellites being in geosynchronous orbit, which is ~40,000km away. This trend will likely slow or even reverse a bit once the big LEO constellations are launched (some are being launched at ~400km altitude). 25ms local ping times (eventually 10ms as the 340km altitude constellations launch) near-term and long-distance pings actually better than fiber. And with enough throughput to actually make a difference vs fiber.
- Robotbeat 9y agoA lot of cellphone connections in Africa and rural locations generally are backhauled by satellite.