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Comment by Piskvorrr | Hacker News Reader

I remember those being used back in the late 90s - when point-to-point radio links were prohibitively expensive and/or too noisy. Is this still worthwhile, other than as a quirky historical device?

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> The device has 1.4km range and has stable 10Mbps full duplex data rate.

I'll go out on a limb and say 'a quirky historical device'.

If the devices could do 10Mbps in the '90s, a similar effort could do much better now.

The range is tricky, especially in fog, but mountain to mountain links (single channel audio) have gone 173 miles.

Nah. I've been looking into this, actually: you're up against all sorts of physics constraints, unless you want to go laser (beam dispersal, air humidity, lens size...), and with lasers, it gets legally tricky. There are technical reasons this hasn't caught on, the 10 Mbps is indeed the theoretical upper limit (people used to lovingly call them "fog density meters").

You haven't been looking very hard, this is a commercial 10Gbps system that does 7 kilometers in clear skies: http://artolink.com/page/why/

I was mainly referring to the hobby builds being able to do better.

In clear skies. Around here, that's a big if - with the other side of the disclaimer reading "...and if the weather is not perfect, you get no link at all." Perhaps useful in other regions, though.

Not true, they offer 10Gbps on 2.5km distance, 7km distance is for 100Mbps with radio backup only.

Since you have way more knowledge in this area than I do, would it ever make sense to use a radio frequency laser (if that's even possible) for point to point communication? Like, to cut down on signal loss and etc. in much the same way as visible light lasers perform better than LEDs. I'm completely unknowledgable about physics, so that may not have made any sense XD but I'm interested in the answer!

It would work better - but I'm pretty sure that the decisive factor was cost: back when this was conceived, getting a useful laser would have driven the cost 10x higher. Plus, I think there's some pesky law on coherent light output power and whatnot (and another which bans lasers outright if you're close enough to an airport).

Aah, makes sense that they wouldn't want to foul up any instruments that rely on RF/microwave. Thanks for the answer :D

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