SpaceX plans worldwide satellite Internet with low latency, gigabit speed

Post by gallerdude » Fri, Nov 18, 2016, 12:36 AM UTC

legolas2412 wrote: post #87

gibybo wrote: post #22

Earlier quoted context omitted.

People aren't generally using a 1 gbps connection at 100% capacity 100% of the time. If we assume customers use an average of 1 TB of data per month and the time they use it is pretty spread out (seems reasonable since they are going to be spread out accross timezones eventually), you can serve about 6 million customers with 800 satelites @ 23 GBPS, and with 4400 @ 23 GBPS you could do ~33 million. Admittedly these n…

But isn't it still cheaper to lay fiber cables? For example, 23*4400 = 101Tbps, but I guess many of the satellites will end up above water, so maybe around 60Tbps. One cable by google did that for 300mil$ [1] Maybe it is good for last mile connectivity, which is probably a good target, but only for less populated areas where LTE isn't available. [1] https://www.extremetech.com/internet/231074-googles-faster-u...

Post by legolas2412 » Fri, Nov 18, 2016, 12:38 AM UTC

Nokinside wrote: post #38

whiddershins wrote: post #2

I don't understand the math. 800 satellites at 23 gbps seems to be able to provide 1 gbps to 18,400 connections at any given time. This seems to be many magnitudes off from what would be needed to have any impact. What am I missing?

It will be expensive bandwidth no matter what. The way they can make this work is if they 1) are targeting traditional satellite internet customers (ships on the sea, commercial aviation, etc) and 2) integration with 5th generation mobile networks trough wireless network virtualization. Mobile network provider can sell a service where traveling customer pays extra for connection that works in the middle of nowhere. W…

Post by grapevines » Fri, Nov 18, 2016, 12:39 AM UTC

Post by cortesoft » Fri, Nov 18, 2016, 12:39 AM UTC

Veratyr wrote: post #56

whiddershins wrote: post #2

I don't understand the math. 800 satellites at 23 gbps seems to be able to provide 1 gbps to 18,400 connections at any given time. This seems to be many magnitudes off from what would be needed to have any impact. What am I missing?

To take home users as an example, the residents generally sleep 8-10 hours a day, work 9 hours a day, commute ~1 hour a day, leaving only about 6 hours of free time at home a day. Assuming they spend that entire time watching 4K Netflix (25Mbit), they'll have used ~2TB in a month, or ~6Mbit/s total. Averaging bandwidth out over the whole month, each satellite would be able to support 3800 people. With the 4400 satell…

Post by elihu » Fri, Nov 18, 2016, 12:39 AM UTC

nickparker wrote: post #14

lettergram wrote: post #3

Does anyone know: (A) the potential lifespan of these satellites are? (B) Why has this not been done to date? I assume SpaceX expects that it'll be relatively affordable since they can reuse rockets. (C) Will this impact the launch capabilities of future rockets (4500 satellites are a lot)? My assumption is that the low earth orbit will likely aid in destroying those satellites as opposed to leaving them up there at…

A) The technical attachment lists the lifespan as 5 to 7 years B) It's a triple play of radically reduced launch costs, rapidly dropping space hardware costs thanks to growth in the market, and improving RF tech to greatly increase the bandwidth such a constellation can provide. Ubiquitous connectivity is a great example of a technology that's going to happen because of the high level industry trends. The interesting…