Will Aironet AP1220B (AIR-AP1220B-A-K9) compatible with WLC4400 with an IOS upgrade? I looked up on notes and docs but couldn't figure out if that particular model is supported to run under Wireless LAN Controller. Or I just have to do an upgrade to another model?
Upgrading Autonomous Cisco Aironet Access Points to Lightweight Mode
Lightweight Access Point FAQ
You are going to need to upgrade to a different model :( Have a look;
For all Cisco IOS Software-based Aironet 1200 Series modular AP (1200/1220 Cisco IOS Software upgrade, 1210, and 1230 AP) platforms, the ability to convert the AP depends on the radio.
If the radio is IEEE 802.11g, MP21G and MP31G are supported.
If the radio is IEEE 802.11a, RM21A and RM22A are supported.
You can upgrade the 1200 Series APs with any combination of supported radios:
Both G and A
From this doc;
EOS/EOL for Cisco Aironet 802.11B-Based and First Gen. 802.11A-Based Prods
Hope this helps!