I was Director of Marketing with Teledesic, Craig McCaw and Bill Gates's Internet-in-the-Sky from 1995 to 2000. I'm a huge fan of what Musk is doing, with order of magnitude cheaper launch costs and satellite hardware. AMA.
How far did you get? What went wrong? What sort of latency/bandwidth did you expect to achieve? Was it relaying via geosynch/higher orbit 'hubs' or peer to peer sideways routing?
We raised $1.6 B, received the largest spectrum allocation in the history of the world (1000 Megahertz, in the Ka band, available globally), and launched one test satellite.
But, the biggest problem with these sorts of systems is that there is no MVP. Essentially everything has to work before anything can.
Our design was for a network of Low Earth Orbit satellites, which would mean cellular-like latency. We were planning to offer tens of megabytes per second, but it would have been really expensive. Our design used lasers for inter-satellite links, so there was no need for lots of local gateways.
In retrospect, the biggest mistake was to try to raise money from the incumbent telecom operators around the world, whose business we should be have been planning to disrupt.
It seems there are still phases you could do. Instead of trying to bring up an entire constellation at once doing two-way communications covering the entire globe, you could start with just a few broadcast-only satellites. Not competitive with at my house in urban North America where wifi and LTE is ubiquitous, but that's never going to be your market anyway.
The receiver on the ground is going to have to be specialized hardware anyway, so build in a battery and a real time clock so it can wake itself up when one of the satellites is in range, and then record everything the satelite is transmitting. Send the entire contents of Wikipedia once a week, send technical manuals, send the week's news, Windows updates, Linux distros; the Internet is so ubiquitous these days but fast access to it is still elusive in remote parts of the world.
This wouldn't have been useful in 2000 but 15 years later, a box with an wifi access point and a 1 TB hard drive chock full of information that's relatively up to date?
Not as cool as "internet anywhere in the world", but a start. Phase in delayed 2-way communication next, reusing the physical antenna from version 1; adding more satellites as you go.
Of course, 15 years later, the cost of putting 1 kg in orbit has also shrunk, and having a WiFi-capable computer in my pocket to look up information on is "normal" - which wasn't so, 15 years ago.
1. As an American-based company, SpaceX would be subject to CALEA [0], meaning that they would have to enable law enforcement intercept of communications with a warrant. This would likely be done by replicating the packet streams at the gateway. However, it's quite possible that you could use the system in a repressive country, without them knowing about it or having a way to stop you.
2) The purpose of the system (and the spectrum) will likely be broadband data, not hand-portable voice. So, it should be disrupting Time Warner and Verizon's cable and fiber offerings, not cellphones. The real value is internationally to have reliable broadband available anywhere.
"The purpose of the system (and the spectrum) will likely be broadband data, not hand-portable voice."
You're unlikely to get one without the other.. if down the road you can get an affordable internet connection on your phone without having to deal with cellular networks, I'd bet that you would see a huge shift to VOIP.
Edit: Whoops, looks like phones probably won't be able to receive this signal practically.
"I believe Musk is, like Teledesic, planning to use the Ka-band. That means the smallest antenna would be the size of a large laptop" [0]
How will devices on the ground communicate with the satellites? i.e. do we still need fixed dishes, or are we looking at something new so an iPhone can get signal right from the satellite?
I believe Musk is, like Teledesic, planning to use the Ka-band. That means the smallest antenna would be the size of a large laptop (and that's only if phased arrays become cheap enough). So, it would work for a car, plane, boat, or house, but would be too big to use while walking.
There are satellite (I think Ku band) dishes for larger (~50ft) boats nowadays. They are using gyroscope assisted motors that wouldn't suffice for compensating rolling motion of a smaller boat.
The laptop-sized antenna he mentioned doesn't need a gyro because it uses phased-array tech. Essentially you resolve signals in any direction (up to a resolution given by number of elements and array size) by carefully combining them with certain phase offsets such that signals from all but one direction cancel out. This adjustment is made on the fly to track a signal with changing direction.
Directionality and sectioning has been used since the beginning of cell technology: first with cell splitting and then with cell sectoring, and recently more aggressive splitting (smaller cells) -- it's an ongoing evolution. The kind of tracking this has required is very easy to do: once your signal is stronger in a competing sector for a significant amount of time, switch sectors. The same principle can be applied to phased arrays but the small number of sectors makes it much more tractable computationally and in terms of hardware.
A phased array in a city environment needs to track in real time the position of users, with enough feedback from them to make sure your prediction matches with their position well enough, and use this information to continuously adjust sub-nanosecond (depends on the freq/bandwidth) phase offsets to array elements. In principle it`s even possible to do multi-tower coherent communication. Needless to say, this tech is expensive right now, and I imagine hard to get to work reliably.
MIMO is also closely related, the difference being traditional MIMO actually adjusts amplitudes only (non-coherent) of multiple data streams to create channels (after a linear transformation at the receiver). This means the signals are still ominidirectional for your wi-fi MIMO. Being non-coherent means it's much cheaper.
1. Among the companies which have announced plans for space-based internet like SpaceX, OneWeb, LeoSat, Yalini etc which do you think can deliver good quality internet at the lowest costs.
2. What according to you is the most likely terrestrial delivery model to succeed. Partnering with local mobile operators/ISP's (like OneWeb) or creating an altogether new infrastructure/gateways/ground stations (like Yalini).
3. I couldn't find details of SpaceX's plans (like throughput, speed, latency, costs, delivery model etc.). Can you refer me to any publicly available information on this.
If Musk achieves reusable launch vehicles, and that had been available to you guys back then, how much would that have changed things for you? Would the system pretty much be up and running today?
We were looking at about $10 K per kg to orbit, and we could barely make the economics work. It looks like SpaceX is offering $4 K. [0] Presumably, reusable launch vehicles will drop his costs another order of magnitude, but they shouldn't actually be necessary to make this sort of system viable.
