256-fold (or even more) increase in speed on copper wire possible IMHO

This is the best response I have seen in this thread.

Those systems also highlights the problems with transferring multiple bits on a symbol.

A transmission path with non-linear frequency and phase response will quickly kill any simple multilevel signaling.

QAM256 seems to be the most that you can get through a transmission path (8 bits/symbol) with reasonable quality on a single carrier. Splitting the signal into several carriers will help avoiding those propagation problems. The DVB-C2 standard allows up to 12 bits/symbol over the cable-TV network and ADSL2+ theoretically up to 12-14 bits/symbols over the telephone wire.

On multi mode fibers, the transmission speed over long distances is limited by the dispersion. Using several colours will allow a much larger throughput.

With single mode fibers, the limiting factor is the throughput of the electronics, but running signal on different wavelengths, the typical throughput for a single transatlantic fiber is 800 Gbit/s (80 colours x 10 Gbit/s).

No problem whatsoever to TRANSMIT it.

*LOTS* of problems trying to RECEIVE it with anything that bears even a passing resemblance to accuracy.

There's the loss inherent in the wires, just as a start - You *MIGHT* get it working on a specific circuit. But change the length (or size) of the wires involved, and I'll guarantee you're going to have to effectively start from scratch to get the mess calibrated to a point where it functions again - Not very "user friendly".

Then there's environmental noise that the wires are going to pick up (I don't care if you ARE using twisted pair. Or coax. Or mungo-shielded-to-the-point-of-ridiculous "magic" wire) At the voltage differences you're talking about trying to discriminate between (and do it fast, and accurately) any trucker keying up his CB within five miles is going to blow your system to hell. Never mind the "noise pollution" of umpteen bazillion cell phones, commercial radio stations, TV stations, phone microwave relays, etc, etc, etc, etc, until you go blue in the face - and that's just the earth-sourced noise generators - let's not even start talking about sun-caused weirdness, cosmic rays, and similar bursts of noise that *WILL* sneak in and bite you on the ass.

So shut up your yapping about it, and DO it.

Hint: Don't quit your day job...

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It's no problem to set up a communication link with a bandwidth enough to support 1000 TV channels over a single cable (though fibre is a better choice). Transmitting and receiving 1000 Gbps and more over one fibre optic is perfectly possible today. There's just the small question of cost.

What you are failing to understand about things like cable TV and satellite TV is that the transmitters that can mix all these signals onto one medium are /very/ expensive. At the receiving end, you have a tuner that picks out just one of the channels - the receiver only handles a few tens of megabits.

It is perfectly possible to make a receiver system that would be able to get all the data on all the channels, giving you the full bandwidth. It's just that to receive these thousand channels, it would be a thousand times bigger and more expensive than a single channel. And that's just for half-duplex - if you want two way communication, you need to double everything.

don't bother : ralph needs to discover by himself Shannon's and Nyquist work, to name few of the obvious and basic laws of communication.

the best thing to do is : ask him to build a proof of concept, physical prototype. Then let him analyse the tradeoffs of latency, distance, bandwidth and cost.

I am very fine with discrete bits, latency = almost 0, which is critical for fast computations.

yg

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Hi Vladimir

No he is not a troll, he is just a bright person that is starting to think about how to improve data transmissions.

He is now testing his ideas on you - "in the real world" - actually on people that *has* practical experience.

Theoretically he is right, but he has not yet "invented"/"discovered" all the filthy signal degrading phenomenas in the transmitter, during transmission and in the receiver - and from the environment; noise signals. Some practical tests will help.

Glenn

He's completely ignoring what he's being told by people who do know what they're talking about and just keeps repeating his claims no matter how much information he's given. He claimed all of the engineers who've been working on data transmission for the past 50 years were just plain too stupid and close minded to percieve his brilliance.

He's a troll.

I doubt it.

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Grant

Well, if he is not _trying_ to be one, he's doing an awfully good job of being one anyway.

No, he's bright only in the sense that Jack Nicholson's character in "The Shining" was a shining example of humanity. One of the things that distinguishes bright people from others is that they're willing to actually learn something. This guy hasn't shown the least sign of that.

No, he isn't. In particular, he's completely wrong about what the state of the art in this field is, and he presents that "knowledge" in a pretty offending style.

The chips are not the problem. What happens between the chips (i.e. noise) is the problem. For example a DSL connection is 'trained' at run-time to deal with cable length, crosstalk and whatnot.

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