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Author Topic: MESH NET FOR EMERGENCY ECOM  (Read 7604 times)
KD4YSH
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« on: March 21, 2016, 10:13:27 AM »

MESH NET great system we use it all the time the best distance in line of sight is 161 miles low power 12 volt. If you have a laptop and a router this is all you need except a few repeaters(mesh) in line works great. Home brew antennas easy to construct the best part is you can send data, pictures, video, and voice without a radio.
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AF6D
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« Reply #1 on: March 22, 2016, 05:30:56 AM »

Are you using the Linksys modemrouters for this?
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KU7PDX
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« Reply #2 on: March 22, 2016, 01:44:20 PM »

For long-range wireless mesh networks, you'll be looking at equipment from Ubiquiti running the AREDN firmware (http://aredn.org/). Even then, you will need line-of-sight to get anything like 161 miles.

If you're working in close quarters or at a single location, I've had success using used Linksys WRT54G routers running the Broadband-Hamnet (http://bbhn.org/) firmware.

2.4 GHz is fairly crowded unfortunately, however Ubiquiti makes 3 GHz radios that fall within our amateur allocation.
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Chris - KU7PDX
ND6M
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« Reply #3 on: March 22, 2016, 02:54:51 PM »

... Ubiquiti makes 3 GHz radios that fall within our amateur allocation.

just a question, isn't most of this stuff encrypted?
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KU7PDX
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« Reply #4 on: March 23, 2016, 02:09:22 PM »

... Ubiquiti makes 3 GHz radios that fall within our amateur allocation.

just a question, isn't most of this stuff encrypted?

No, none of it is encrypted per FCC rules and regulations.
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Chris - KU7PDX
K5LXP
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« Reply #5 on: March 23, 2016, 09:30:49 PM »


Not sure where this stuff is going.  I got on board with BBHN V1 and having a self configuring wifi network is a cool thing.  Add in some IP phones, cameras and client laptops and in a localized setting mesh is a practical and useful setup.  But now AREDN seems more about becoming a ham ISP, to step in "when all else fails" and provide "served agencies" with (internet?) connectivity.  What I'm missing is why anyone would want AREDN's version of this.  You take Part 15 equipment that supports encryption and includes perfectly capable (and qualified/supported) software and install tweaked version of OpenWRT that adds mesh.  But in a point to point installation what value does mesh add?   It's not like if a node goes down on a mountaintop or tall building somewhere the mesh will reconfigure - the narrow beamwidth antennas required for long haul links won't support that.  Seems misplaced.  Keep the Part 15 radios the way they are with robust software and encryption included, and use mesh for the "last mile" sites.  With such limited hardware support (single vendor & specific models) and being a hobbyist hack to an open source project with very few volunteer players, I can't see anyone taking this as a serious backup to anything.  Then there's the endless debate of using 10 vs 44 address space, those that want domain routing and those that don't.  Meanwhile, commercial mesh over 3G, 4G and beyond is something "served agencies" can simply buy, turn on and use with their own networks and equipment.  HSMM using consumer routers was a neat hack and maybe the code can be ported to something besides a WRT or a handful of ubiquity units which extends the life of the idea a bit longer.  But I'm not seeing what makes this idea deployed in the same way and places commercial networks are, running beta/experimental code crippled to Part 97 requirements is going to be useful or even usable for the purposes AREDN aspires to.  If the "served agencies" wanted this kind of system they can just buy these Part 15 link radios and install them themselves, retaining all the model features, vendor support and encryption.  What am I missing?

Mark K5LXP
Albuquerque, NM
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K7RBW
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« Reply #6 on: March 26, 2016, 08:10:29 AM »

MESH NET great system we use it all the time the best distance in line of sight is 161 miles low power 12 volt. If you have a laptop and a router this is all you need except a few repeaters(mesh) in line works great. Home brew antennas easy to construct the best part is you can send data, pictures, video, and voice without a radio.
I'm missing something, here...

According to http://www.qsl.net/w4sat/horizon.htm, you can only get 161 miles line-of-site if your antennas at each site are over 3,000' above the intervening terrain.

Do you get 161 miles in a point-to-point, line-of-sight configuration (i.e. between two stations), or is that the net distance by various links and repeaters (i.e. the mesh) ?
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K5LXP
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« Reply #7 on: March 27, 2016, 08:18:57 AM »


There's nothing magic about mesh that improves distance or bandwidth performance.  The one thing that adds an advantage to turning a Part 15 device into a Part 97 one is the ability to (legally) change antennas, increase power and (where possible) move the operating frequency to a less congested channel or band segment.  If you have access to mountaintops and tall buildings you can span some useful distances, 10 - 20 miles and sometimes more.  But in order to do that you need necessarily narrow beamwidth antennas, usually dishes.  So whatever you're using for point to point links isn't good for wide area coverage.  It's difficult to get any wide area coverage at all so you end up switching bands, usually to 2.4G for local nodes.  But range on that is quite limited, unless again you go with narrow beamwidth antennas.  For wifi access (clients not wired directly to a node) you need to create a wifi access point, which adds another layer of complication in terms of throughput and range.

Not trying to beat up on BBHN and AREDN.  For a basic mesh LAN this stuff works pretty well.  Where it falls down is when you try and scale it to the level of a WAN and try to turn it into a ham ISP.  The commercial solutions out there right now are way better and there's just no way Part 97 HSMM on consumer devices is going to accomplish anything on that scale.  Better I think would be to improve the local/field deployed aspect of mesh so that it's a plug and play solution for hams creating a quick field network.  Retain the feature of installing it on cheap consumer hardware going forward so that it's simple, quick and inexpensive for any ham to set up and use.   I think there are far more applications for that than a select few trying to play ham radio hero by providing a crippled TCP/IP pipe to some served agency.

Mark K5LXP
Albuquerque, NM

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KD4YSH
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« Reply #8 on: March 27, 2016, 08:28:11 AM »

The 161 mile test was done out west from mountain top to mountain top, on flat land depending on obstructions you can usually get from 3 to 15 miles or more. The thing they do is station points of communication 10 miles apart or more like they did in Oklahoma when the tornado's hit and the normal communications were down. The system of the mesh network for hams is to transmit voice, video,still pics and more.
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KC2MMI
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« Reply #9 on: March 27, 2016, 11:33:15 AM »

"The thing they do is station points of communication 10 miles apart or more like they did in Oklahoma"
 Would live to see some specifics, since microwave is generally line-of-sight and that's only three miles over flat unobstructed ground when both antennas are six feet above that ground level. Range claims that actually rely on antenna height or mountaintop-to-valley are pretty meaningless in the larger world when terrain and installation aren't specified.
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KU7PDX
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« Reply #10 on: March 28, 2016, 02:23:11 PM »


For a basic mesh LAN this stuff works pretty well.  Where it falls down is when you try and scale it to the level of a WAN and try to turn it into a ham ISP.

I really couldn't agree more! It's really designed to be a LAN and there are much better solutions for point-to-point backbones and/or trunking.
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Chris - KU7PDX
KB8VUL
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« Reply #11 on: March 29, 2016, 07:31:51 PM »

One thing to realize about all this.  If you are using it for ham, and running really high gain antenna's and modified firmware that allows you to crank up the power then you are OK in the ham bands.  The minute you are using the high gain antenna's and such and running high power links outside of the ham band allocation or for commercial use, it becomes illegal.  the reason for all the RP (reverse Polarity) connectors and other oddities is the idea to keep high gain antennas and amplifiers off of the ISM WiFi bands.  While factory firmware will hold you to under 20mw, very high gain directional antenna's can get you way over the legal ERP (effective radiated power).  Cisco actually had their units require the antenna system gain be put into their units so it could turn down the RF power to a legal level if someone connected it to a 20db directional antenna.  This was because at 20mw into a 20db antenna the ERP is 2000mw or 2 watts. That is WAY over the legal ERP for WiFi hardware in a standard commercial installation.
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K5LXP
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« Reply #12 on: March 30, 2016, 03:09:20 AM »

The minute you are using the high gain antenna's and such and running high power links outside of the ham band allocation or for commercial use, it becomes illegal.

For 2.4GHz consumer gear that's absolutely true.  But the Part 15 equipment offered on 5.8GHz allows a much higher ERP and gain antennas.  The HSMM guys running equipment on that band are using off the shelf Part 15 stuff.  Very few if any of the point to point links are 2.4GHz for numerous reasons. 

Mark K5LXP
Albuquerque, NM
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