I found this interesting:http://arstechnica.com/tech-policy/2012/09/lightsquared-redux-fcc-blamed-by-lawmakers-who-lack-tech-expertise/

congress critters ignoring their committees duties, then when they don't like the outcome which was based on science they go after the people in charge. The company gambled they could figure out a technological solution to allow their high power transmission in spectrum next extreme lower power and not have it wash out the lower power signal. Now congress wants them not to lose money.

The Former Banker, that was an interesting story. What I found disturbing was not the fact that the House committee didn't understand the technology -- we can't expect the House to have experts on every known field -- but it was the fact that they were determined to remain so, expressed in Stearns repeated demands for a yes or no in a question that's too complicated to be answered that simply.

One of the most touching and important films I've ever seen: "Diameter of the bomb." It's about the Jerusalem bus bombing in 2002.

http://www.youtube.com/watch?v=5hLLqD7WqCg

It's free on Youtube or Netflix.

Ars keeps repeating some misstatements regarding the Lightsquared issue. I was involved in an extensive discussion thread over there in February where a bunch of us hashed it out. I'll try to summarize what the technical issue is:

GPS signals are transmitted from satellites that are a long ways away -- about 12,000 miles from the surface of the Earth. Plus, being satellites, the only power they have is what they can collect from the Sun using solar collectors, which means that their transmitters aren't very powerful in the first place. Add the distance to that, and you wind up with a signal that is incredibly faint by the time it arrives at a receiver on Earth's surface. That's why the FCC generally does not allow Earth-based and space-based transmitters to be on adjacent frequencies.

Now, about radio reception and filters. The highway analogy mentioned in the Ars article really isn't very good. Radio signals aren't really in specific lanes -- they're more like blobs that are solid on the inside, get fuzzy around the edges, and then fade into nothingness as you move further away. Powerful radio signals are blobs with large solid cores. Weak radio signals are blobs with very small cores and lots of fuzzy edge. And all of the blobs overlap some out around the fringes.

For a receiver, capturing a strong signal is easy -- you just need a piece of that solid core. So you can build a receiver that isn't very sensitive; it'll get enough of the core to work with, and those fringy areas won't be a problem because the receiver isn't looking there. However, if the desired signal is very weak, it's important to build a highly sensitive receiver that will capture all of that fuzzy edge, in order to get enough of the signal to work with. The problem is, when you do that, you also get some of the adjacent signal. That's not a problem when both signals are weak, but when the adjacent signal is strong, its fuzzy edge may well be stronger than the entire blob that you're trying to capture.

That's what the GPS receiver is faced with. It's trying to grab the very weak GPS signal from space, while the far stronger Lightsquared signal is blabbing away right next door. It's faced with a dilemma -- if the receiver is not sensitive enough, it won't get the GPS signal, but if it is sensitive enough, it captures part of the Lightsquared signal, which drowns out the GPS signal. This sort of thing can sometimes be addressed with filters. Now, the "sharpness" of the edges of filters is measured in decibels per octave, or dB/octave. Filters of 12 dB/octave are common in radio designs; 24 dB/octave is considered a pretty sharp filter. I did the calculation myself for the sharpness of the filter that the GPS receiver would need to filter out the Lightsquared signal, using some numbers from the test mentioned in the Ars article. I came up with about 130 dB/octave.

That's a ridiculous filter. It can be built with current technology, but it definitely would not fit in a hand-held device. I'm thinking it would be at least the size of a cereal box, would not be capable of running on batteries, and would cost hundreds of dollars. And I don't see any technology advance in the near future that would change that. At the very least, it would be the end of embedded and hand-held GPS receivers. No more smart phones with GPS built in. And that still would not be enough for critical applications, namely aircraft navigation.

Now the political concerns. The Lightsquared investors have been reckless. In my opinion, they have been so because they have well-documented deep connections into the White House, and they gambled on crony capitalism to see them through. They bought a spectrum license knowing that it was restricted to space-based applications, then they applied to the FCC for a waiver to use it for something not permitted by the license. Let me repeat, they figured the FCC would fold because of their White House connections. And apparently they never consulted with an engineer; any competent electrical engineer could have told them that they were going to run into this problem. Hell, I worked it out myself, and I'm a software guy.

The makers of the GPS receivers do not own the GPS spectrum. They only build receivers, and in the U.S. you don't need a license to build a receiver. The Department of Defense owns the GPS spectrum, and GPS has been using that spectrum since the early 1980s. Lightsquared's suggested solution is the ridiculous filter, which would kill most of the market for GPS devices and cause a safety problem for aircraft. In effect, they are trying to say that they are going to interfere, and it is the responsibility of the party experiencing the interference to deal with it. That's like saying that I'm going to start a pig farm next to your house, and if you don't like the smell, it's your problem to seal up your house and install an expensive air-filtering system. The only other possible solution that the receiver makers and the DoD could pursue would be to either move GPS to another frequency or make changes to the transmission standards, either of which would make all existing receivers obsolete.

So the FCC (God help me I can't believe I'm about to say this) did the right thing. They denied Lightsquared their waiver. Lightsquared can still use their spectrum for the licensed purpose if they wish, or they can sell it or trade it. The only thing they have lost is something they never had in the first place. But apparently they are now having a temper tantrum and they're going to set as many oil wells on fire as they can on their way out. Bunch of immature narcissists.

On an entirely different note: just read about a study linking psychopaths to poor sense of smell. I never thought about it, but it makes sense. You know. Like if you have a house full of bodies, that sort of thing.

Then there's the guy getting that lovely settlement over the popcorn-lung thing. Burying his face in the bags to suck up that smell. (Never mind how I feel the judgment, I just like the smell connection.)

I've read that "invisible scents" are responsible for some of the unlikely male/female relationships one sees. Not pheromones, an actual smell that you just don't really register, but you're drawn to it.

Smell. Think about it, won't you? Thank you.

Which brings us to the book Perfume, about a man with no personal smell of his own, who is eventually both a perfumiere and a serial killer, after he becomes obsessed with the scent of prepubescent girls. I guess he didn't read the study.

They made a movie of it, but I don't know much about it. Typical, I just looked it up. They go on about his great sense of smell, but I didn't see any mention about him not having a smell of his own. That was what repelled people, and the whole reason he joins the perfume business and learns the power odors have on people. He makes himself smell different, depending on what he wants from others.

I wonder if they kept the original ending. Not pretty.