TDMA at 65k feet on a ras pi 2

[charles at thefnf.org]

Hi all.

For the past year, I have been working with a team of ~20 folks across 
the world on "internet balloons". Essentially a DIY version of Google 
Project Loon. The idea is to provide commercial internet service on a 
permanent basis for ~5.00 per user per month. It will be open 
source/open access/DIY.

We've settled on using FreeBSD due to it's TDMA and 802.11s support. All 
around this seems to be the most mature / turn key implementation 
readily available. Payload is essentially a solved problem at this 
point. I have a Rasberry Pi 2 (or whatever the latest model with the 4 
usb ports is) and a GPS HAT from Adafruit. This gives me a FreeBSD 
network node and highly accurate GPS timing. So far so good.

I would like to know what the best USB Wifi dongle to get. I have tried 
to piece it together from the FreeBSD Wifi wiki and various PDFs I've 
found, but wanted to do a quick ping to the hive mind for the most up to 
date recommendations. Obviously one with an external antenna connector. 
:) I've got various Alfa USB cards lying around, some rt link stuff and 
other random dongles. I'd like to shortcut the typical trial/error 
process if there is a magic unicorn USB dongle option.

It seems the intersection of TDMA + 802.11s + USB makes the selection 
somewhat.... interesting.

Feel free to point me at the manual and say RTFM if that's the best 
path.


Thanks all!