Ryan: Alex, SpaceX live streams their launches from the rocket. How?

Alex Gizis: I really wanted to know this so I went to Stack Exchange and someone named Bob Jacobson answered this. Anytime you're doing anything over radios you have to file paperwork with the FCC. So it turns out SpaceX filed the plans for how they were going to do the video with the FCC and it's really interesting.

They have these special digital video transmitters that broadcast on two frequency bands at the same time by a company called Quasonics. So there are two bands right around 2 GHz. It's not 2.4 GHz. And they beam down the video on both channels at once. So it's a real problem on a rocket, both because it's moving fast and those flames coming out of the bottom of the rocket are plasma. They're making static, radio static. So it's really tough. So to make sure the video gets through, they send it twice. So they're receiving on both bands and putting it together. So any bits that get through, they combine and that's how they managed to get that video.

Ryan: Redundancy. It's pretty funny because Speedify can do that without special equipment.

Alex Gizis: We do have that redundant mode where we'll make sure that every packet goes over at least two internet connections and we'll deliver whichever one gets through first. If you're doing that over two wireless links with a digital video encoder connected to it, that's basically the same thing, isn't it?

Ryan: Yeah, I mean, that's what the BBC is using.

Alex Gizis: Right, right. Nick Garnett, we had him on, we interviewed him a while ago, and he was talking about how when they send people out of the radio station to do man on the street interviews or go cover live sports events, they take a Raspberry Pi, they put Speedify on it.

They'll hang off three cellular modems and connect their computer to that. So then they're out live streaming and it hits Speedify. We send on all three modems, deliver whichever one gets through first. They can have one or two modems completely stop working, or they can have one get really terrible latency or loss for a while.

And we just grab the fastest, lowest latency packet that's right and send it through so they can have all kinds of terrible things happen. It always just works. The audience notices nothing.

Ryan: So going back to the SpaceX launch, you mentioned that they use radio waves. I've seen on the Starlink website the satellites communicate with space lasers. Are they in the mix at all?

Alex Gizis: At the beginning, the way it worked with SpaceX, it was radio waves up to the satellite that bounced them down to you for your internet. And it worked awesome. But, there had to be a base station close to you. There was something usually within a hundred miles, and that's why there were, even though there were satellites, there were some spots they covered and some spots they didn't.

Well, now they can beam it up to one of the satellites, and the satellites can send a laser through space to another satellite that's over an area that they don't have a base station. This is how they service the airplanes in the middle of the Atlantic, the ships in the middle of the Pacific. They're going radio up to the satellite, and then the satellite is bouncing lasers To the other satellites until it finally comes down to the ground.

Ryan: Is that Lifi or is that something different?

Alex Gizis: I believe it's something different. So Lifi is the standard that got announced a few years ago for doing internet over light.

They talked about smart light bulbs beaming internet to your laptop at faster speeds than Wi-Fi could go at. I don't see any products at all for sale for consumers to use this stuff. If you look at the Lifi website, they say it's actually being used by some airplane companies to beam internet to airplanes as they fly by. But it doesn't actually say lasers, and certainly SpaceX doesn't say that they're using Lifi. So I think it's something different, but probably some similar concepts in there.

The late, great Dave Isherwood once told me a story. He was doing IT at a Wall Street bank, and they had two buildings, but there was a third building in the middle, and they needed to get really fast internet between the two for their real time trading. What he ended up doing was finding someone whose apartment in New York could see both buildings and they paid that person to mount a mirror in their window and then they bought communications lasers and they actually shot them into the mirror and it bounced off to the other building where they mounted the laser communication system there as they had two way super high speed laser communications between the two bank buildings in the late nineties.

Ryan: Was that something you could buy back then? Like a laser router?

Alex Gizis: I don't think it was cheap, but yeah, it was, it was a thing. The point is, I don't think Starlink is using Lifi. I think they're just buying communications lasers and doing it themselves.