Upgrading Cisco Aironet AP from autonomous to lightweight

If you are using 1130AG or 1240AG access points, congratulations you can upgrade from autonomous to lightweight.

For all IOS-based 1200 series modular access point (1200/1220 Cisco IOS Software Upgrade, 1210 and 1230 AP) platforms, it depends on the radio:

–if 802.11G, MP21G and MP31G are supported

–if 802.11A, RM21A and RM22A are supported

The 1200 series access points can be upgraded with any combination of supported radios: G only, A only, or both G and A.

Do a "show controllers" command to see which radio chipset you are using.

http://www.cisco.com/en/US/docs/wireless/access_point/conversion/lwapp/upgrade/guide/lwapnote.html