What I took from the CQ article is that it depends on why you're encrypting the traffic.  They mentioned network security and access control, and also repeater control codes.  This sticks  out to me because not only is a mesh node basically a repeater, but the admin pages for each one are unencrypted.  When you log in, the root password for that node is going over the air in plain text.  (Of course, something like WPA would prevent the casual listener from seeing this, but if the key could be obtained or cracked somehow, this would be moot.)

I think that using SSL for the admin page (ie, giving it an https:// url) would be a wise idea.  It would require some work on the firmware, which I am looking into, but I think it could be done technically.  Without it, there is the possibility of a casual WiFi sniffer to lift the password and tamper with a node.  If the mesh is being used for something like emergency communications a measure like this would be very important for the stability of the network.  Of course, the workaround is to just access the admin page only through a wired connection and never through the mesh, but this could be impractical for a remote site.

I finally found some time today to do some comparisons between directional antennas. We didn't have enough time to test my omnidirectionals, so I'll have to test those another day. There was a light rain/snow falling, so that may have affected the results. But the intensity of the precipitation remained pretty consistent through all my tests, so hopefully the results are valid in comparison to each other.

For the first round of tests the nodes were 2.9 miles apart in a mostly rural area. There were some houses between them but not nearly as many as in a suburban area. And both nodes were high enough to have a clear line of sight. One end used a cantenna made from a soup can. At the other end I tried several antennas and got these SNR ratios:

Cantenna: 5
MFJ-1800 yagi: 9
Hyperlink 19dbi parabolic grid: 12
Hyperlink 19dbi parabolic grid + 500mw amplifier: 25

We noticed that the MFJ-1800 was much more sensitive to being aimed in exactly the right direction than the other 2. But it had significantly less wind load than the parabolic grid.

We then drove to a spot that was 5.9 miles from the first node. There was now a small town between the nodes but most of the area was still rural. It was still half raining, half snowing lightly and the wind was blowing harder. We had an unobstructed line of sight back to the first node. My fingers were getting cold enough that I didn't stay long enough to try all the antennas. I measured these SNRs:

Hyperlink 19dbi parabolic grid: 10
Hyperlink 19dbi parabolic grid + 500mw amplifier: 21

I was pleased with these results given that one end of the connection was just using a soup can antenna and that we had light precipitation attenuating the signals. I was surprised that the 500mw amplifier on just one end of the connection made as big a difference as it did; I had expected it to add half as many db as it did.

I want to thank KC7OY for standing out in the snow with me and helping to conduct these tests. It would have taken much longer if I'd done them alone. I'm planning to do another round of tests in an area where I can have a 20 mile unobstructed view. But I've got some travel and other events coming up, so it may be a month or two before I get a chance to conduct those tests. I'll report back once I do.

I'm highly skeptical. 

If it does work, you'll need to be sure it's precisely aligned vertically.  It's got to have a narrow vertical pattern if it's got that much gain. 

There's probably some basic physical limitation that an omni antenna of x wavelengths can only have a gain of f(x). 

It's 15 inches long, which is 3 wavelengths.  As a very crude estimate, assume that's like 6 dipoles stacked up on top of each other.  A dipole is roughly 2 dbi.   6x power is 8 db, giving around 10 dbi.  Real antennas are probably less efficient.

As I said, that's definitely a SWAG guess.  I'm not an antenna expert.

Are the Ubiquiti Nanostation LOCO M2 compatible with the mesh firmware?  What about the Bullet M?

From what I read, seems like maybe it's not supported yet, but will be soon?

I found the following FAQ entry.

http://hsmm-mesh.org/section-blog/37-hardware-faqs/56-how-long-will-a-wrt54g-run-from-a-battery.html

2.4GHz 20dbi RP-SMA Male Wireless WLAN Booster Omni Antenna Booster

Just ordered a couple of these.  Does anyone have any experience?  It just seems too good to be true that you can get the same gain as many of the dish antennas with a glorified rubber ducky.  That said, even if it is only 10-15dbi, it should more than do what I need done.

Anyone else have any insights?

KE7YKP

I built a biquad using the data here http://martybugs.net/wireless/biquad/

This antenna was very impressive for it's size.

I added it to a dish.

This setup works quite well. Combined with a 2W amp on each end, was able to do a 9.6 mile link with another station that is using that 24dBi grid antenna with a 92% link quality.  The bare biquad actually was able to do the link as well. Don't have link quality data, but it showed up on the signal strength screen.

I suppose I could measure the current draw...but I didn't want to make a lab project out of it. I may have to do that since I don't see the info anywhere here or on the DD-WRT sites.  May checkout Cisco site first.

Greg, Matt, Steve,

There is a substantial interest in this project at the Mississauga club http://marc.on.ca now and we are looking to make a pilot installation for the Field Day.

We were wondering if it is possible for a few of us to come to one of your club meetings or meet you elsewhere and have a longer discussion on the subject, share the experience and ideas. Would it be possible to meet with you around mid- or early-May?

Thank you,

Anthony

VA3IDL

Thanks for the info, I'll be getting some equipment then!

By the way, great site here with a lot of good information.  I had been thinking about why Hams seem to be stuck at 1200 and 9600 buad, and then found this site.  Now there are some options to move data at some higher speeds.

Will

KB8YGA