With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cDot11ActiveWirelessClients
Cisco Dot11 Active Wireless Clients
1.3.6.1.4.1.9.9.273.1.1.2.1.1
This is the number of wireless clients currently associating with this device on this interface.
Back to CISCO-DOT11-ASSOCIATION-MIB MIB page.
IPHost Network monitor allows you to monitor cDot11ActiveWirelessClients on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco mobile switches right now.