Feild Day Mesh Network - Antenna, Distance, and Checking signal strength

I recently went out to our site, where Field Day will take place, with a few of our club members to see about how we are going to setup logging. A few of them are bringing RV's and things like that and so we need a way to network our systems together.

The preferred logging software is N1MM Logger which works rather well on PC, and seems to do "ok" under wine on Linux. The challenge is getting the data feeds from the internet and sharing them out amongst our dispersed stations. So I thought this is a great place to show case mesh net, and play around and see how it works in a real test environment.

To run my test I brought with me my laptop running a linux program called iwScanner that works in python. It works amazingly well, if you're looking for something on windows then I recommend ViStumbler. Unfortunately it doesn't work on Linux.

I also brought with me two routers to test out and the first one looked like the signal was going up and down. I ended up switching to the other one. We got out to probably about 300 or 400 yards with a -80 or so db in signal. Which I think would still put stuff through just not very fast. This was however just a router with it's stock antenna, chucked into the rafters and through light trees.

I think that's pretty promising that we will be able to connect these together. So when I got home I decided I was going to build a Omni directional Collinear antenna. Following the directions from Marty Bug's website (Which is a great resource for all wifi antenna design) I set out to build one. I wanted to get the most db gain possible so I just cut a super long piece of wire and started with that. It's about 5' long and I had a bit of trouble placing it into a electrical conduit (pvc). As a result the loops on the antenna probably got shrunk and I wouldn't be surprised if it is a bit twisted up inside.

With the stock antenna on my mesh node I got about -17 to -22 db. With the one I created I get a steady -33. Now this is only preliminary tests and I have some modifications to the end of the antenna to try out. Also because it is a lot bigger the vertical beamwidth is smaller.  So I probably have to try it upright and a bit farther away. Otherwise I'm back to the drawing board on the omni wifi antenna.

The next antenna that I'm going to build is either a bi-quad antenna or a quad-quad antenna, which can also be found on Marty's website. Also with this design at some point I plan to install it onto a dish to give it a bit more gain and direction.

Field Day isn't until the end of June so I definitely have quite a bit of time to get these solutions up and going. Of course it doesn't help when I plug in 48 volts power supply into one of my only 2 12volt rated nodes and just about catch it on fire.

At some point I'll post some pictures.

Mesh Net for Emergency Communications (EmComm)

WB2IFS' Meshnode setup

So I've been looking into meshnet pretty heavily since I discovered it and got my Amateur Radio Operator license. My goal is to be able to set up a mesh network in my county and surrounding area so I've been looking at different software that would work well for file sharing, chat, and various other forms of communication.

There are various types of mesh networks out there but I'm specifically interested in Broadband-Hamnet to be able to set it up locally. With the right equipment I don't think that we would have any major issues in the area I live and getting 54gbps up to 10 miles away in the right conditions. The benefit of the mesh network is that each node can talk to each other node and it can self repair so to speak. The drawback is that it can be rather bandwidth intensive as each node on the network has to know about each other.

My goals are to be able to transfer, voice, video, files, over a mesh network using a raspberry pi(s) as the server on a self sustaining node. Ideally all of this would be decentralized and self replicating but I will have to worry about that at a later date.

Here's a brief run down of the hardware that I'm investigating.

• Linksys WRT54G routers
• Raspberry Pi
• Older Scrapheap cheap PC
• Cantenna
• Omni Directional/Colliner Antennas

Software that I'm investigating.

• GetSimpleCMS - For website to contain basic information on the other services, ability to give out generalized information on events or issues
• Openfire - Openfire is a XMPP/Jabber server software that can allow for voice, video, file transfer and text chat
• OwnCloud - For setting up drag and drop file sharing functionality.

My core goal with these is to make the setup a simplified as possible and hand out the information for my club members to be able to set up their own nodes or software. Making it as simple as possible and step by step which I will be posting here also.