With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
frxPortSpeed
Cisco 90i Port Speed
1.3.6.1.4.1.1570.1.6.1.1.1
This is the speed that the channel unit port runs at. 1=56kbps 2=64kbps 3=128kbps 4=144kbps This parameter can only be changed if frxConfigSrc is set to SNMP.
Back to CISCO-90-MIB MIB page.
IPHost Network monitor allows you to monitor frxPortSpeed on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco wireless switches right now.