Re: OT: The Truth About Predator Drones

Doh! I think I went the wrong way with the 3db and 4.77dB differences. I get stuff like that backwards all the time.

I'm less skeptical now. ;)

Yer nuts.

You need to keep up. BGAN is real, and there are BGAN radios being used. They are not 15 years old, and no, it is not the 6 cubic foot form factor Motorola gear, it is less than one cubic foot.

Just so you know, it DOES use WiFi, if needed, as well as other link methods.

You have no clue what is involved.

I doubt you even know what a conduction cooled assembly is, and you exhibit more and more that you have little clue about the guts as well, despite any training or experience you may have.

These two are like a bad episode of 'Spy VS Spy' in a '60s Mad magazine. :(

Except SvS was funny.

Know what you are taking about. The USA is a G20 member, so are Britain and Japan.

Andrew Swallow

Okay, we're in sync, even if our hypothetical modem isn't.

Right.

The AWGN channel exhibiting 10% raw BER is still 3 dB less noisy than rate 1/3 BPSK capacity, and popular binary convolutional codes generally start functioning when you're 2 dB to 3 dB from capacity.

The near-channel-capacity codes are generally functional around 1 dB from capacity, sometimes less.

Steve

Yeah, we're on the same page. Since the context was a satellite link, I'd still be skeptical that anyone would bother to use an R = 1/3 code over a satellite, just because of the spectral efficiency (since transponder bandwidth is muy expensive). For R = 1/2, which is more believable, my skepticism remains healthy.

Remember: this is military money. Those birds are $30 million a pop.

Jerry

You're right in that the rate 1/2 convolutional code (which is very popular for SATCOM and is specified for such use in MIL-STD-188) just misses working at the 10% raw BER channel condition point. For noisier satellite channels it's more popular to lower the signalling rate than it is to lower the code rate.

(We could also have a philosophical discussion as to whether adding spreading constitutes lowering the code rate...)

Steve

You're talking to AlwaysWrong.

Yer nuts. Satellites are $400 million each, and that is a commercial bird!

AlwaysWrong gets it wrong once again. The "bird" in question was the Predator, not the Satellite, DimBulb.

I did say it was bad, didn't I? :(

Predator, ijit!

Jerry

Actually, it is difficult for you, because it is not a public key system.

snipped retarded playground child horseshit

Yeah, asshole... it's called 'Link Budget'.

You're such a dumbshit, AlwaysWrong. *ALL* crypto systems require key management. Indeed that's the downfall of most. Unlike you, DimBulb, key management is *not* simple.