Stardate 20020606.1939

(On Screen via long range sensors): I found this article via Moira Breen just before I went on vacation, and I've been thinking about it off and on ever since. It describes the basic difference in philosophy which is driving the perceived split between the US and Europe politically and militarily, including the European "new way" of deemphasizing military power and relying more heavily on diplomacy to deal with crises instead of naked force.

I think I can formalize my basic objections to the European approach now, but it's going to take some explaining. We need to talk about a couple of words, and to explain them I'm going to have to use examples from engineering. I hope the going doesn't get too rough; bear with me.

The words are sustainability and scalability. They refer to things which we engineers have to take into account when proposing solutions for things.

Sustainability refers to the fact that no solution lasts forever. The sustainability of a solution is a matter of degree, not a question of yes/no. No solution is infinitely sustainable; everything eventually fails. When we as engineers design something, we don't try for permanence because permanence can't be achieved. What we try to do is to design something which will last longer than we need it to, and which will fail gracefully rather than catastrophically when the time comes.

For instance, I used to be responsible for the code in Qualcomm's cellphones which manages the time of day and keeps track of it. (And does a lot of other things, like scheduling periodic execution of events, and some things I'm not at liberty to discuss.) The time is stored in a field of a certain bit-length, and like all such fields, this one will eventually overflow. In fact, in about 350 years, every cell phone based on IS-95 which uses my code (which is to say, about 95% of them) is suddenly going to start saying that the current date is sometime in the 17th Century. However, I considered that reasonable because the only place these phones will exist by then is in museums. It's not infinitely sustainable, but it's going to last until after it's replaced by something better, and that's good enough. One way or another, those phones won't be in use when that failure occurs, so it doesn't matter.

"Sustainable" means that it will last until we don't need it anymore, probably because it's been superseded by something superior which later, more sophisticated engineers will design.

Scalability refers to whether a small solution will still work practically if it is used heavily or used for larger problems. There's an entire branch of computer science which seeks to try to characterize how algorithms increase in compute cost as the size of the problem they're solving increases; people in that field tend to wander around muttering phrases like "NP-complete". But scalability is bigger problem than that, and one we have to constantly be aware of. Not all solutions scale well; some don't scale at all. Sometimes when you try to scale a small solution the result is catastrophic.

Traditionally, radio tended to use narrow bands, tailored to the needs of a single carrier frequency. Television bands in the US are 5 MHz wide, but they need to be because of what they're transmitting and how it's encoded. The phones I used to work on use what's known as "spread spectrum", which means that the phone uses a 1.2288 MHz bandwidth carrier frequency to transmit information at a rate no greater than 14.4 kilobits per second. That's massive overkill, but spread spectrum has a number of interesting characteristics and advantages, and the entire cell phone industry is moving to it.

The reason it doesn't waste spectrum is that lots of phones use that 1.2288 MHz carrier simultaneously. Because of how the data is encoded, they can all transmit at the same time on the same carrier frequency without anyone getting confused. The new 3G phone systems use a carrier which is even wider, three or four times as wide, in fact.

One proposal was for very wide spread spectrum. Instead of 2 or 4 MHZ, use something like 500 MHz. Now the effect of doing this is to smear the energy being transmitted very widely, and when it is examined on a narrow-band basis it is so low as to be negligible. The proponents of this system can't actually identify 500 MHz of unused spectrum to use, but they're trying to claim that they don't need to. Lay it on top of existing spectrum allocations. It will cause so little interference on them that existing licensees won't even notice it.

Which is true but only if there are only a small number of people using the very wide spread spectrum system. Each of them adds a negligible amount of interference to the narrow-band users, but if there are millions of them the sum will cease to be negligible and the narrow-band users will no longer be able to do what they're licensed to do. You can't ignore Shannon; bandwidth isn't free. If you use it, no-one else can. The problem with very wide spread spectrum is that it doesn't scale.

There are a lot of things which don't scale. I've written about pacifism here, and one of the problems with it is that it doesn't scale. In American society there are (simplistically) three kinds of people: villains, pacifists, and good guys who are willing to fight to d