<OT> Frank, this is a bit dated, but if you have not seen it, here is a layman's, but interesting, conceptual discussion about Doug Humphrey's SkyCache concept. As you say, though, it is hard to evaluate the economic tradeoff unless someone calculates the pricing dynamics of terrestrial high-speed networks.
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On a slightly different topic, I agree with your comments on the Teledesic concept, but every time I look at it I cringe with worry about the subtleties involved in operating a low-earth constellation that has to be so tighly synchronized. There are a lot of unknowns, among which are problems inherent in linking information across orbital planes. Unlike a terrestrial network, or even a constellation of satellites in the same plane (or geosynchronous satellites), the problem with a Teledesic concept is that you may have to pass information to a moving target (a different satellite), whose position is constantly changing at high rates, both in orientation and range. I am familiar with some of the ways they are attempting to minimize the technical challenge, but it is still formidable, and could result in large packet losses. I am reminded, though, of a talk I heard by J. Licklider, father of the ARPANET, who was describing the lack of standards in the internet as both its weakness and its strength. As he described it, the internet only has one standard: you push a bunch of packets in one end, and some packets come out the other end. Teledesic should be able to comply with this standard. |
