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#164 - New Ham Radio Mesh Network Project

A few local hams along with myself are getting together to design and build an off-grid mesh network that will link our computers together with wireless access to each other across the island.

This mesh network will also give us the ability to use IP based phones in a disaster situation where landlines, cellphones, electricity, and internet are out of service.


This process will use standard 2.4 GHz wifi equipment with software that has been modified, similar to how the Amateur Radio Emergency Data Network (AREDN) is set up, yet with additional capabilities that AREDN does not offer.



Because of the location of my house, I will have a base station set up which will utilize one of these 12 dB gain 120 degree sector antennas.


Where this will be installed will allow me to have access to the majority of the south side of Oahu from Ewa Beach to downtown Honolulu.


If I add on a second sector antenna facing to the west or utilize a 180 degree sector antenna instead, I can extend that coverage to include the entire south side of Oahu. Anyone who has line of sight to that antenna can connect to the mesh.


With my house being a little over 300 feet above sea level, most of the south side of Oahu would have line of sight to my antenna.



For portable stations out in the field, we will utilize a dish style antenna like the one below which is much more powerful and can be erected on extendable antenna masts and tripods, then pointed towards one of the base antennas to connect to the mesh network.

This will be a long drawn out project that will take a while to put together and get all the bugs worked out of, but we should be able to have everything complete before hurricane season this year.


We also utilize 2.4 GHz wifi routers, just like you have in your house now. We just flash them with new software which changes their frequency slightly over to frequencies within the amateur radio band.


We are also looking at the possibility of adding on a 5.8 GHz backbone along with the 2.4 GHz side of the mesh network, but that is going to take much more thought and planning. We know that it is possible, and easy to do, yet we are trying to decide if this option will be viable and cost effective.


As frequency increases, the line of sight range decreases, so a transmission on a 5.8 GHz frequency would not travel as far as the same transmission on a frequency in the 2.4 GHz range. This would work for mesh nodes that are close to each other, but would not work for nodes that are farther apart.


As I said, I lot more thought has to go into this, so for now we are concentrating on the 2.4 GHz mesh network so that we can have it deployed and ready before hurricane season this year.


I will update you along the way as the system progresses.


Until Next Time,

Aloha & 73


 


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