In addition to a strong signal strenth - signal quality is also VERY important. It sounds like you have some sort of interference. You have to identify the source of the interference. You can use tools like Cognio to assist you with this. Have you tried using different channels? Do you have the same behavior using the 'A' network?
Cognio is company which supplies the product 'Cognio Spectrum Expert for Wifi'. Its a spectrum analyzer which will enable you to get a full view of the wireless spectrum. Note that this is a combination of hardware and software.
From what you have stated, my guess is you have over-saturation and co-channel interference(cci). Cci happens when you put all your APs on a single channel. Only channels 1,6, and 11 do not overlap. try arranging them as such and review your power levels.
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...