AIR-AP1840I-F-K9 Cisco Aironet 1840I Indoor 4x4 MU-MIMO Access Point

AIR-AP1840I-F-K9 F-Domain Aironet 1840

AIR-AP1840I-F-K9 is the F-domain, controller-based Cisco Aironet 1840 indoor access point. It combines a 2x2 2.4 GHz radio with a 4x4:4 5 GHz 802.11ac Wave 2 radio and four internal antennas.

F-domain channel boundary

Cisco's data sheet lists thirteen 20 MHz channels at 2.412-2.472 GHz, four at 5.250-5.350 GHz and four at 5.725-5.825 GHz for the F domain. These published ranges do not replace approval for the actual deployment country or controller enforcement.

Controller and software gate

The exact PID ends in -K9, not -K9C. Treat it as the controller-based ordering form rather than promising a factory-shipped Mobility Express image. Cisco documents Unified Wireless Network 8.8 MR2 or later and IOS XE 16.12 or later; confirm the intended controller and current compatibility matrix before staging.

Power and receiving checks

The AP provides two autosensing 10/100/1000BASE-T ports, takes PoE on Ethernet and draws 13.2W at the PSE with all documented features except USB. With USB enabled Cisco lists 17.8W at the PSE. Record the F-domain label, serial, mounting kit, negotiated power and both Ethernet links.

Lifecycle decision

Cisco ended sales on 30 April 2022 and sets 30 April 2027 as the last date of support. Catalyst 9115AX is the stated migration family. Remaining support time, controller software, regulatory approval and replacement timing should be reviewed together.

Compare AIR-AP1840I-K-K9 and AIR-AP1840I-H-K9 only when the destination's approved regulatory identity calls for those distinct PIDs.

Official evidence: Cisco F-domain channels and Aironet 1840 specifications, Cisco installation and PID format guide, Cisco exact PID lifecycle notice and Cisco wireless compliance lookup.