Longer-haul wireless

[Mercutio]

I have a classroom site that is presently served by the world's slowest DSL. On a very good day (as in, I saw it one time while the telco people were on premises), it speedtests as high as 384kbps but is normally in the 128 - 192kbps range.
I have two other sites within three and a half miles of that location that each have 100Mbit cable connections. As one might imagine, this causes considerable frustration, especially since about half that bandwidth on any given day is going toward the one receptionist's Iheartradio.com habit. Never mind that she has a clear line of sight to the Hancock building, where most of the FM transmitters in Chicago are located. She'd rather listen on her computer.

I've done modest amplified 802.11 installations where I didn't need much more than a reasonably high power transmitter and an off the shelf directional antenna pointed in the general direction to get a good signal over maybe a couple city blocks between two buildings, but in those cases I had a clear line of sight.

I'm thinking that I could put up a couple antenna towers and stick directional antennas on each side and pass 802.11AC between two sites. I have a decent handle on what the 802.11 equipment needs to be like, but I'm less sure about the antenna heights and costs. It looks like a 40 foot mast is relatively cheap, but I'm not sure if it's going to be tall or sturdy enough.

Has anybody done this sort of project before?

 

[Chewy509]

Not using regular 802.11 gear... But if both sites have clean line of site, then could you consider FSO (Free Space Optics) instead? You can get 1Gb links, but a 100Mb links are very cheap these days.

Since most FSO based technologies rely of lasers you don't need to worry about interference from other RF sources, intercept of the signal requires getting directly in the signal path, etc...

A quick google brought up these links:
http://en.wikipedia.org/wiki/Free-space_optical_communication
http://www.lightpointe.com/freespaceoptics.html
http://www.freespaceoptics.org/

 

[ddrueding]

For that short a distance LOS might not even be necessary. Get a pair of the cheap-ish Ubiquiti panels and point them generally towards each other. You might even get away with having them in the building envelope. I have dozens of such installations that haven't needed to be touched in years.

https://www.ubnt.com/airmax/nanobridgem/

 

[mangyDOG]

For that short a distance LOS might not even be necessary. Get a pair of the cheap-ish Ubiquiti panels and point them generally towards each other. You might even get away with having them in the building envelope. I have dozens of such installations that haven't needed to be touched in years.

https://www.ubnt.com/airmax/nanobridgem/

Second vote for the ubnt stuff. Easy to configure and here in AUS I have a choice of 5Ghz, 2.4Ghz or 900Mhz radios.

 

[ddrueding]

Here we have the same along with a few others. Perhaps a site survey before buying the gear would guide you toward the right frequency to choose.

 

[Mercutio]

So I'd be looking at getting a dish, a PoE injector if I want to run it outdoors and probably a Rocket M5 AC Lite on each end?

That seems completely reasonable.

 

[ddrueding]

The radio is cheap, but the antenna can be expensive. I'm also too lazy to assemble them myself. PowerBridge M5 works great.

http://amzn.com/B004EZBYUM

 

[Mercutio]

That looks like a WISP-class device rather than a point to point bridge which I think is all I need. I suppose I'll have to email someone at Ubiquiti.

 

[ddrueding]

I've bought about a dozen of the exact item that I linked to, all for use in point-to-point connections. Everything I've bought from them uses the exact same interface and supports all the various connection methods.

 

[Mercutio]

I've bought about a dozen of the exact item that I linked to, all for use in point-to-point connections. Everything I've bought from them uses the exact same interface and supports all the various connection methods.

dd, what if anything are you using for an antenna/aerial for your installations? Do you just have clear line of sight in all cases?

 

[ddrueding]

dd, what if anything are you using for an antenna/aerial for your installations? Do you just have clear line of sight in all cases?

The ones I linked to have the antenna and radio in the same unit. Just put a PoE injector at the bottom and you're done. I don't always have line of sight, but it (of course) helps. The web interface has some handy tools for aligning the antennas. Also keep in mind that all the units of a similar class have about the same power output, so the longer the claimed range the narrower the beam and harder to aim.

My normal install is a 20' long 1.5" diameter steel pipe bolted to the side of the building and sticking up 8 feet or so. That way I can mount it while standing on the roof. The mount for most of Ubiquiti's units is just a couple u-bolts that go around the pipe and attach to a bracket. Double check the size of the u-bolts before ordering the pipe. Black (UV resistant) zip-ties down the pipe and lead the cable into a vent under the eve.

 

[Mercutio]

Neither of the sites where I could potentially source my connection will let me put up an aerial to mount my antenna. I could still do it from my apartment, if I felt that strongly about making it happen. My apartment is facing the wrong direction and I'm not sure I have any rights to mount stuff on the roof, but it appears that if I went with 900MHz Rocket M9 and LocoM9 devices, I might still be able to manage a relatively high speed link. Since absolutely any speed that starts with "Megabit" is faster than what they have, that might be my best option.

I'm half tempted to buy an M5 and mount its antenna on my apartment roof to just see how well a Nanostation M5 works from a window mount, but that's an awfully expensive experiment.

 

[Mercutio]

On a somewhat related note, I just bought a couple UAP-LR access points that supposedly have a range of 600 feet. These are for an unrelated project, but I was kind of curious if they would work, especially over that kind of distance and I need to buy access points anyway.

 

[Mercutio]

So the real-world range improvement from a UAP-LR over a standard $40 Trendnet AP? I'd say it's around 20 feet or 6m (in radius) in an open floor cubical farm area. That's not nothing but it's also nothing terribly dramatic. Ubiquiti claims 180m range and I'd say it's off by 130m or so.

 

[ddrueding]

So the real-world range improvement from a UAP-LR over a standard $40 Trendnet AP? I'd say it's around 20 feet or 6m (in radius) in an open floor cubical farm area. That's not nothing but it's also nothing terribly dramatic. Ubiquiti claims 180m range and I'd say it's off by 130m or so.

Wow. Interference? Saturated channels?

 

[Mercutio]

There weren't any other 2.4GHz 802.11 sources in the immediate area, according to my site survey.

 

[Stereodude]

Are they using aluminum foil as wall paper?

 

[Mercutio]

The outer siding of the building is aluminum, now that I think of it. Though I've put APs in similar buildings without issue. I'll probably see what happens if I turn the Tx power down next time I'm out there.