They have a dish antenna that is 28dBi gain, and it can only manage 54Mbps at 19km. Also, panel antennas aren't as focused as dish antennas. So your performance will be less than this.
Still, 6dBm seems a bit low, but wireless can be unpredictable. If you want to troubleshoot this, you'll need to buy/rent a spectrum analyzer and take it out there to see if there's any interference. You might need to realign the antennas a couple times for optimal connection.
You can also disable the slower data rates one at a time and see whether your bridges can handle the higher bandwidth. Definitely don't put the bridges in production this way, but it at least removes the automatic selection aspect from the equation.
Transferring Crash file from standby: Login to the Active WLC in HA.
From CLI: (Cisco Controller) >transfer upload datatype crash (Cisco
Controller) >transfer upload filename (Cisco
Controller) >transfer upload mode tftp (Cisco Controller) >transfer
This is the start of a display filter cross reference between Wireshark
and OmniPeek. The 1st installment is a table of advanced filters. More
filters will be added as time allows. It is a living doc, so check back
for changes every so often Please feel f...
I have created a Powershell script to automatically add a Wireless Guest
User on Cisco WLCs. (tested on 2500 Series) The script should be
completely self explanatory. Prerequisites: Powershell SNMP Module
(Install-Module -Name SNMP) SNMP Write Access to y...