Scientists In Japan Build 100Gbps Wireless Network Using Terahertz Transmitter 49
Mark.JUK writes: A group of Japanese scientists working on a project managed by Hiroshima University claim to have successfully built a Terahertz (THz) transmitter, which is implemented as a silicon CMOS integrated circuit and can transmit a signal running at 10Gbps per data channel over multiple channels in the 275-305GHz band for a top speed of 100Gbps (Gigabits per second). But crucially nobody has mentioned the distance at which this speed could be achieved, particularly since the THz band isn't likely to have much of a reach. It also sits very close to the region used by lasers.
Huh. (Score:2, Insightful)
TIL lasers have their own band in the EM spectrum.
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That sampling theorem got blown out by any real audio technician that uses pitch-shifting.
That theorem is NOWHERE CLOSE to being adequate for any situation where pitch-shifting is a requirement. You need at least 32x the sampling rate to achieve near-flawless pitch-shifting up or down to a MEASLY TWO WHOLE NOTES, NO MATTER WHAT THEIR FREQUENCY RANGE.
I've proven it with .FLAC files, .RAW files, .WAV files, and .PCM files, across every pitch-shifting plugin known for the most popular media players.
Shannon-Nyq
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That band is called "light", hence the 'l' in laser.
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>Which laser operates at 300 GHz?
Masers [wikipedia.org]
.
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It's not really a Laser then if it's a Maser.
Same principle of operation, but it's reasonable to expect light to come out of a laser, yes.
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Microwave lasers. EM can still be directed and made into coherent beams no matter the wavelength. Wave-particle duality FTW, son. Go back to basic physics class in high school. Oh, wait, you're likely one of the NCLB generation.
How close to the lasers' region? (Score:1)
It also sits very close to the region used by lasers.
Within firing range?
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Yes, I agree with you. The only possible explanation that I can come up with is that they must have dubbed the next order of ten over EHF as "The Terahertz Band". If that's the case, it needs a better name. If we are to assume that they are keeping with the general pattern used for radio signals, then this band would go from 300 GHz to 3 THz.
This would be an extension of the standard used to class radio waves into bands of an order of ten, which gives us VLF (9-30 kHz), LF (30-300 kHz), MF (300-3000 kHz)
Nyquist can stop spinning. (Score:1)
TFA says "and now another team claims it can hit 100Gbps by pushing into the TeraHertz (300GHz+).". Nyquist can stop spinning.
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That doesn't actually preclude physics. We can get multiple bits of information from a single photon. QAM, frequency, phase-shift, etc. The theorem still holds across almost every perceivable 'sound effect' until you get to the matter of pitch shifting, in which case, even with the minimum 2x sampling rate, the reality is that you need about 32x that amount to get an accurate signal representation that won't distort across a wide range of frequency shifts.
There's a reason Nyquist-Shannon has a "THEOREM" ins
real world testing (Score:1)
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Wouldn't even register. 2.4 GHz is so far out of the tuned range it's not funny.
Yes But? (Score:2)
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No.
That is all.
Why is this a network? (Score:2)
This looks familiar (Score:2)
100 gbps isn't that fast (Score:1)
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Terahertz signals would only reach 10's to maybe 100 meters, AND they're blocked by metal or water.
(i.e. a human standing next to the router might cause significant signal loss). Probably good enough
for indoor use, though --- at 100 gbps you could afford to retransmit lost packets.
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Who's using 100Gbps wireless links for cellular backhaul?
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You're off by at least two orders of magnitude. Sprint's wireless backhaul links (that they inherited from Clearwire) are 1Gbps at most - the vast majority are 100Mbps or less.
But what would I be downloading? (Score:1)
100 Gbps is roughly 14 gigabytes per second. So I would use up my 5GB monthly Verizon cap in about 1/3 a second, then begin racking up $10 /gig overages at $140/s.
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How do you come up with those figures?
I get a theoretical maximum of 12.5GB/sec and I've _NEVER EVER_ encountered a wireless data transmission system that comes anywhere close to it's apparent maximum. Ever.
Wireless A,C,N,G etc - all of them, you should basically divide by 8, as standard and then halve it again. If you're lucky, maybe you'll get 60% of the claimed maximum, maybe.
I would imagine a 100Gbps system to give a real world figure (pulling this directly from my ass as I type this,.. based on experi
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