441–450 of 526 posts
Earlier quoted context omitted.
Just in: Musk offers to buy City of Montreal
2 months before deciding to reneg due to too many fake people in Montreal. He accuses the City of Montreal of hiding the true number of thugs and criminals.
A bit unrealistic no?
It says 350 Mbps per plane. How much does it translate to per seat? Say if all passengers start a video call or a S̶t̶a̶d̶i̶a̶ Nvidia GE force game, then?
A network that is not oversubscribed and provides full non-blocking throughput to downstream devices is by far the exception: high-end datacenter spine/leaf systems come to mind as an example.
Earlier quoted context omitted.
To use Starlink you need to have a line-of-sight to the satellites, and that basically requires you'll get to install the ceiling of the whole building and even that might not be enough, right? To do that you probably need to get the whole building (or the building manager) to go along with this. So if you have 1/3000 of people wanting this in the city, those same people also need to be in a matching situation to hav…
That‘s true, yet I‘m seeing a lot of TV satellite dishes even in major cities, when cable TV is arguably also readily available. If people want it, at least some of them will find a way with their landlord, if they don‘t already own the entire building (especially in the US, single-family homes are not at all uncommon close to the center of major cities).
Interesting. In which country do you live in? Because in France, I'd say that 90% of the people owning a TV sat dish are immigrants looking for the channels of their country of origin (the type of things you usually don't get with cable network), and the other 10% are people in very remote areas.
Earlier quoted context omitted.
> Like sending Ukraine "free" base stations and charging them $4,500 a month for service. Are there any alternatives? Nope. Also, let's not talk about how SpaceX "should" sponge up the costs, because you would not ask Lockheed Martin or Raytheon Technologies to do that. Compared to regular prices of military hardware, Starlink costs nothing.
To get any credit for 'charity' we should at least look at the nominal cost to service a particular base station instead of the cost to make Starlink profitable. For the former I only really see the bandwidth costs because the base stations are part of Starlink's normal operation and all of the satellites are up there anyways.
Edit: a fatal assumption that it's the airlines providing the service underpins my original post below, whereas instead it's the providers charging passengers directly. That's an entirely different model from below, so disregard my original comment aside maybe my last line. Preserving the comment for context though. --- At 25,000/mo, assuming a jet makes 60 trans-con segments in the US per month and a price of $20 pe…
Earlier quoted context omitted.
Interesting. Is it based on 4G/5G or something ad-hoc?
It's basically LTE in the 2.4 GHz band, with a load of extra bits for beam forming, coping with speed and distance etc. Using the 2.4 GHz band allows them to build a network covering the US without spending billions on spectrum. Yes, it's the same 2.4GHz ISM band that wifi uses, with the same power limits. And yes, it works well enough that you can do video calls hundreds of kilometres from the base station. That's h…
That's not really fair. Their solution requires knowing the exact location of the base station and the client at all times. It's significantly more complex and expensive than Wifi.
Won't this require spectrum licensed from every country the plane fly's over? Easy in North America... But all other regions of the world a typical flight might go over 20 countries. If you can't secure a license for just one, you're gonna have a 5 hour flight with 20 minutes of no internet... Not great. And I don't think they're getting a license for Russia, Iran, China, half of Africa, etc any time soon.
Earlier quoted context omitted.
Let’s not forget that this could be a value add, they can easily increase flight ticket prices by $20 and offer the service for free. They can also remove inflight monitors from the planes, reducing the weight of the overall plane, increase plane tickets by $10 and offer it Free. There’s many ways to play with the numbers
Not sure they'd need to go as far as removing the IFE completely, but a vastly more simple and cheap system could be used instead. Airlines still rely on those massive clunky boxes under each seat, plus a server rack which adds a fair bit of weight. Swapping to an all-in-one system - essentially a smart tv built into each monitor that just provides a browser and basic apps for major streaming services would reduce th…
Earlier quoted context omitted.
It's basically LTE in the 2.4 GHz band, with a load of extra bits for beam forming, coping with speed and distance etc. Using the 2.4 GHz band allows them to build a network covering the US without spending billions on spectrum. Yes, it's the same 2.4GHz ISM band that wifi uses, with the same power limits. And yes, it works well enough that you can do video calls hundreds of kilometres from the base station. That's h…
> That's how shit wifi Seems like you know a bit about this. Could you indulge my curiosity and elaborate why wifi is shit? I assume some combo of DSP bottleneck (i.e. want to keep hw cheap) and maintaining backwards compatibility with older standards?
Multiple Access - this is the general term for 'multiple devices on the same spectrum'. Cellular divides up the spectrum into frequency bands (Frequency division multiplexing) and time slots in those bands (time division multiplexing). The base station then assigns each device a slot in a band (or potentially several), it also provides the time reference for this scheduling. This makes efficient use of your available spectrum and nothing interferes with or talks over anything else.
Wifi gets none of this. There's no base station planning so two access points can interfere with each other. There's no FDMA (access point runs on one channel of one band), and no TDMA. There's no uplink channel and downlink channel separation. Instead it's "Carrier sense with collision detection". Basically "try not to transmit at the same time as someone else, and if you do come back and try again later". This results in nodes competing, talking over each other, interfering (see "hidden node problem") etc. and makes inefficient use of the spectrum. The problem gets worse as the traffic gets busier. Wifi 6 is bringing in some actual scheduling.
Modulation schemes (the fundamental way that you transmit bits on a radio) - cellular modulation schemes are now incredibly efficient and robust. They use a variety of techniques that allow scaling based on channel conditions so that you can get as close as possible to whatever Shannon currently says you're allows. A lot of wifi uses old-school spread spectrum, and newer standards use OFDM which is a bit better. Wifi 6 is finally moving to the Quadrature Amplitude Modulation stuff that LTE uses.