Friday, April 24, 2015

AREDN first site on the air

I've installed the first of what I hope are many AREDN (Amateur Radio Emergency Data Network) mesh nodes. This site is located on a large grain elevator in Heyworth, IL. It's at the 150 foot level, with two yagi antennas. One antenna is pointed north towards Bloomington, and the other is pointed northeast.


I'm still going some testing with the antenna configuration - with guidance from the AREDN group, it looks like I need point both antennas in the same direction to take advantage of how 802.11 works. I wanted to try to reach two distant locations with this node...the better way to do that is to have two nodes with directional antennas - at least that's what I'm going to try next.


The node is made up of a Ubiquiti Rocket M900 node, two RP-SMA to N jumpers, and two yagi antennas. The node is fed with a CAT5E cable that provides Power over Ethernet (POE) up to the node, and data in both directions. This arrangement results in very little loss - there's nearly no coax. 

This site also houses a UHF analog repeater and the KD9AKF D-STAR repeater. Using vlan capable switch, I am able to create a connection to the internet from this mesh node. It isn't meant to be a replacement for personal use internet - but having the ability to route to and from the internet means I can access services from either side of the mesh as allowed by amateur Part 97 rules.

What's next? I'm working on two more nodes - one is a portable setup that I'm still experimenting with. I'm going to try a 12 mile link to the top of a parking garage sometime. What's interesting to me is playing in the 900MHz ham allocation. So far, 900MHz for this application behaves much more like microwaves than UHF - it does penetrate some structures and obstructions. 

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