Troubleshooting Tip: FortiAP 6GHz radio shows channel 0 and 'channel usable: disabled' despite correct configuration

Description

This article describes when an AFC-supported FortiAP is configured in outdoor mode and deployed in a country without AFC service (e.g., Mexico), the 6GHz radio stays disabled — showing channel usable: disabled, channel: 0, and the 6GHz VAP stuck in INTF_DOWN.

Scope

FortiAP - All 6GHz-capable models configured in outdoor mode, including:

• FortiAP-234G, FortiAP-432G.

• FortiAP-241K, FortiAP-243K, FortiAP-244K.

• FortiAP-441K, FortiAP-443K.

Countries affected:
Any country where 6GHz LPI is approved but AFC Standard Power service is not available.

Solution

In 6GHz, there are two regulatory power classes:

When the WTP profile is set to indoor-outdoor-deployment outdoor, the FortiAP attempts to operate at Standard Power, which requires AFC authorization. In countries without AFC service (such as Mexico), the AP cannot obtain AFC clearance for any 6GHz channel, so the radio remains disabled with channel usable: disabled and oper_chan: 0 as the following example:

Output from the command 'cw_diag -c radio-cfg':

Radio 2: AP
   country        : cfg=MXO oper=MXO
   countryID      : cfg=484 oper=484
   sta info       : 0/0
   radio type     : 11AX_6G (pure AX)
   mimo,chainmask : 4, 0xf (mimo) 0xf (power) 0xf/0xf (oper)
...
   txpwr mode     : set by percentage (100%)
   txpwr cfg/oper/max : 50/50/50 (EIRP +11)
   HE param       : gi=disabled bw=160MHz
   ack timeout    : 25
   r_ac MAX dista : 0 ackt_2G=64 ackt_5G=25 
   r_ac ht_cap    : gi=0 bw=3 bw_ext=1
   r_ac chan      : num=0 age=611407
   channel usable : disabled
   channel        : num=0
   oper_chan      : 0
   r_ac md_cap    :   1,   5,   9,  17,  21,  41,  45,  49, 
   r_ac chan list :   1,   5,   9,  17,  21,  41,  45,  49, 
        chan list :   1,   5,   9,  17,  21,  41,  45,  49, 
   hw_chan list   :   1,   5,   9,  13,  17,  21,  25,  29,  33,  37,  41,  45,  49,  53,  57,  61, 
                     65,  69,  73,  77,  81,  85,  89,  93, 
   nol list       : 
   chutil meas    : enabled
   sensor mode    : disabled  (applied promisc mode=disabled)

Troubleshooting steps:

1. Collect FortiAP output for tech support.

fap-tech

Look at the 6GHz radio section for:

• channel usable : disabled

• channel : num=0

• oper_chan : 0

2. Check the WTP profile indoor/outdoor deployment setting on the FortiGate:

show full wireless-controller wtp-profile

Look for 'set indoor-outdoor-deployment outdoor'.

3. Check AFC status on the FortiAP (if available):

cw_diag -c afc status

If AFC is not available or not completing for the country, this confirms the root cause.

Change the WTP profile from outdoor to indoor mode:

Via FortiGate CLI:

config wireless-controller wtp-profile
    edit <wtp-profile-name>
        set indoor-outdoor-deployment indoor
    next
end

Via the FortiGate GUI:

1. Navigate to WiFi & Switch Controller -> WTP Profiles.

2. Edit the WTP profile used by the affected FortiAP.

3. Change Indoor/Outdoor from Outdoor (default) to Override, and then select Indoor.

4. Select OK to save.

After the change, the FortiAP will receive the updated profile via CAPWAP, and the 6GHz radio will operate in LPI mode without requiring AFC. The radio should come up with channel usable: enabled and a valid oper_chan.

The following document can be used to validate standard power regulation in each country:

Regulations Enabling 6 GHz Standard Power Wi-Fi

Important:

• Indoor mode restricts the AP to LPI power levels. If the AP is physically deployed outdoors, the 6GHz radio will operate at reduced power (LPI limits). This is a regulatory requirement, not a bug.

• If outdoor Standard Power operation is required in a country without AFC, 6GHz operation is not possible until AFC service becomes available in that country.

• Always verify the country's 6GHz regulatory status before deploying FortiAPs with 6GHz radios in outdoor mode.