AIR-AP1840I-B-K9C Cisco Aironet 1840I 4x4 MU-MIMO Mobility Express AP

AIR-AP1840I-B-K9C B-Domain RF and Software Record

AIR-AP1840I-B-K9C identifies the B-domain, Mobility Express form of the indoor Aironet 1840. The AP supports four spatial streams at 5 GHz, two at 2.4 GHz, four internal antennas and dual Gigabit Ethernet.

B-domain four-range channel set

The data sheet specifies eleven 2.4 GHz channels at 2.412-2.462 GHz, eight 5 GHz channels at 5.180-5.320 GHz, eleven at 5.500-5.700 GHz and seven at 5.745-5.865 GHz. Confirm legal channels and power for the installation country through Cisco's compliance record.

Primary AP continuity

Because K9C was shipped with Mobility Express, a replacement may be expected to recover an embedded-controller role. Record software version, country, AP inventory, client scale and configuration export. Test primary election and rollback before removing the existing controller AP.

Thermal and power gate

The published operating range reaches 50C, but Cisco notes that above 40C radio transmit duty cycle may be limited to no more than 50 percent. Verify ambient temperature, PoE mode, USB usage, Ethernet links and actual radio duty under the intended mounting location.

Support horizon

The exact B-domain K9C PID appears in Cisco's retirement announcement. Catalyst 9115AX is the migration family and support ends 30 April 2027. AIR-AP1840I-F-K9C is not a substitute because its channel plan is materially narrower.

Official evidence: Cisco B-domain channels, thermal and interface specifications, Cisco Mobility Express model guide and Cisco B-domain lifecycle notice.