Hi Ardjan,
Have you tried this method?
CLI Configuration Example
This example shows the CLI commands that you use to enable multiple BSSIDs on a radio interface, create an SSID called visitor, designate the SSID as a BSSID, specify that the BSSID is included in beacons, set a DTIM period for the BSSID, and assign the SSID visitor to the radio interface:
router(config)# interface dot11 0
router(config-if)# mbssid
router(config-if)# exit
router(config)# dot11 ssid visitor
router(config-ssid)# mbssid guest-mode
router(config-ssid)# exit
router(config)# interface dot11 0
router(config-if)# ssid visitor
Requirements for Configuring Multiple BSSIDs
To configure multiple BSSIDs, your access points must meet these minimum requirements:
VLANs must be configured
Access points must run Cisco IOS Release 12.4(6th)T or later
Access points must contain an 802.11a or 802.11g radio that supports multiple BSSIDs. To determine whether a radio supports multiple basic SSIDs, enter the show controllers radio_interface command. The radio supports multiple basic SSIDs if the results include this line:
Number of supported simultaneous BSSID on radio_interface:
From this good doc;
http://www.cisco.com/en/US/products/ps5853/products_configuration_guide_chapter09186a008067e9f6.html
Hope this helps!
Rob
