I've done this before. The problem with the free-space optics is they're incredibly sensitive to anything that might come in the way of the link - like birds, rain, snow, drones, anything you can imagine! Also the range is very limited. A free space optics link with a failover to unlicensed RF link works pretty well.

Although tbh it's not that difficult to deal with RF licensing, depending on where you are exactly.

Maybe http://www.koruza.net ?

This looks very interesting. How real is this? Looks like they had targeted Nov 17 to ship. Anyone know if there are units out in the wild?

What is the range on that?

"Up to 150m"

Oh I'm blind. I didn't see that, thanks.

Heard abaout a University which used this to connect the Network in two Tours in the eighties. Place had a lot of fog and birds- so there where problems, but connection was fast.

Highrises would be generally better for this approach- or some long atenna/tethered drone. At this stage though, wouldnt it be rather cheaper, to build a little softrobot and have it drag fibre along preexisting cable channels/stormdrains/sewers - basically just doing the infrastructure decent for cheap yourself.

There are existing solutions that use robots to install fiber optic cables in storm drains, sewers and other ducts. Not that cheap, but the biggest problem is that you need permission of the infrastructure owner to do it.

Terrabeam tried during the .com boom, but couldn’t get it cheap enough. Ronja is a open source 10mbit optical link. I ‘m not aware of any attempts in the past few years to do this though.

Like others have said, optical works best in areas with clear weather for most of the year. In addition, tall buildings move alot, to it works better on shorter structures.

Could any radio engineers weigh in on how practical ultra-directional radio antennas could be for this? I'm imagining collimated radio beams (like lasers) which could bypass the need (not necessarily the existing legislation) for spectrum regulation. What if every house had a few microwave drums on the roof?

Very practical, that's how some backhaul works(and why you see giant microwave dishes on mountain towers).

This Ars[1] article does a great job covering what goes into it. I know of more than a few WISP out there in WA state. They can't do the same data rate as fiber but getting a connection is pretty straightforward if there's any large mountains nearby.

[1] https://arstechnica.com/information-technology/2015/11/how-a...

This is kind of starting to happen with 60Ghz radios becoming more available. I think the problem with 'ultra-directional' radio antennas is that they're actually pretty difficult to build and even when they can be built they're very large. But with 60Ghz there is a lot of oxygen absorption, meaning that the signal dies off really quickly in all directions meaning that it won't interfere as much with other nearby installations. The equipment is just barely coming on to the market, though.

60 GHz PTP bridges have been around for 8 years or so, at 1GbE line rate. They're not rocket science, exactly, but knowing how to properly engineer a network with them is something that not every ISP can figure out.

Are you thinking of the siklu ones or someone else? I'm not aware of any that have been around that long (not arguing just curious) I was thinking of the IgniteNet and MiktoTik versions which I think are both more recent as well as PtMP applications which (I think?) Aren't really generally available yet.

True on knowing how to properly use them! Although to be fair I think most of the ISPs using them don't have a lot of use for really short, high capacity backhauls they're often looking for distance in rural areas.

Bridgewave shipped 60 GHz products 6 years before Siklu... Ignore the Ignitenet, it's a USB 802.11ad dongle glued into a radome. It's a toy. The Mikrotik doesn't have the reach to be a serious product. You can use "real" 60 GHz PTP stuff at five nines at 500-600 meters distance in a moderate rain zone, the mikrotik is good for maybe 90 meters.

Ah yes I forgot about Bridgewave. Agreed on all points for infrastructure needs. I would only add that when I read the OP (of this thread)'s comment I imagined using very very short/inexpensive 60Ghz links from neighbor to neighbor to create a kind of mesh. Possibly not what OP had in mind but it's the way I interpreted it. For that use the MikroTiks might actually make a lot of sense. (Very cheap and low range.)

Edit: Also since you're obviously knowledgeable about this stuff and I don't see a way to contact you on your profile - I've been running a matrix chat room around some of this stuff and would love to have you join! https://riot.im/app/#/room/#startyourownisp:matrix.org

I am a radio and network engineer, we use 71-86 GHz band FDD point to point 1 Gbps to 10 Gbps radio products extensively. One good example of a commercial ISP user that has publicized their use of such is Webpass (since acquired by Google) with their rooftop sites in the SF bay area.

Also potentially https://common.net/ though I’m not sure which specific transmission mechanism they use.

Oh hey I work there. We're using mostly 5ghz wireless gear.

I saw them mentioned in another HN thread recently. From the photos on their web site, they use Ubiquiti gear (probably the Ubiquiti airMax LiteBeam) which runs on 5ghz.

https://support.common.net/hc/en-us/articles/115001438367-Wh...

NYC Mesh.

https://nycmesh.net/