WiFi radio in "superchannel" mode: regulatory limits switched off

What the audit found

A wireless interface on your router has its Frequency Mode set to superchannel. In this mode the radio ignores the channel and transmit-power limits of the selected country and offers every frequency and every power level the hardware is physically capable of. The intended use is licensed operation and laboratory testing, where the operator is responsible for staying within their permit.

The audit reports this as medium when the WiFi regulatory check is enabled and a superchannel interface is enabled. The severity does not depend on your firewall; this is a compliance and interference issue, not a network exposure.

Why it matters

Each country limits which frequencies unlicensed WiFi may use and how strongly it may transmit. In Europe the 5 GHz band is split into ranges with different rules: some for indoor use only, some requiring the radio to listen for radar (DFS) because weather and aviation radars share them, and some — 5725–5875 MHz, channels 149 to 165 — not permitted for ordinary WiFi at all. Power is capped at 20 dBm on 2.4 GHz and 23 to 30 dBm on 5 GHz depending on the range. Other regions have their own tables.

Superchannel mode removes all of that. The radio will happily transmit on a forbidden channel, at full amplifier output, without listening for radar. The practical consequences are interference with radar systems and other licensed users, degraded service for nearby WiFi networks, and legal exposure: national regulators do investigate interference complaints, and operating outside the permitted limits is an offence in most jurisdictions, with the operator of the device liable.

Superchannel is often enabled by accident — copied from a point-to-point link configuration, or turned on to "unlock" a channel that appeared greyed out. On a normal access point it brings no benefit that a correctly set country does not also provide, and any gain in range from excess power is bought at other people's expense.

What it looks like in Winbox

Open Wireless → WiFi Interfaces and double-click the interface. On the Wireless tab, Frequency Mode shows superchannel instead of regulatory-domain, and the Frequency dropdown lists every value the chipset supports, including ones outside any legal band. The Country field may be set correctly and is simply being ignored. Note the Frequency and Tx Power values alongside it. The Wireless → Country Info window shows what the legal ranges for your country are, for comparison.

How to fix it

The fix is two settings that belong together on the interface's Wireless tab: Frequency Mode back to regulatory-domain, and Country set to the country the device physically operates in. The first tells the radio to apply a regulatory table at all; the second selects which one. Setting the country alone does nothing while superchannel mode is active, which is the usual reason this finding survives a first attempt at fixing it. Every wireless interface needs checking, since the mode is set per radio.

After the change, two things may happen. If the interface was on a frequency that is not allowed in your country, it will move to a permitted one — leave Frequency on auto or pick a legal channel explicitly. If Tx Power Mode was set to a manual value above the legal limit, the driver clamps it; switching it back to default lets the router use the correct value automatically.

Clients reconnect briefly when the interface reconfigures. If you manage the router over that WiFi, keep a wired path available, or use Safe Mode so a lost session reverts the change. If the link genuinely requires operation outside unlicensed limits — a licensed point-to-point link, for example — keep the licence documentation with the configuration and restrict superchannel to that interface only, with exactly the frequency and power the licence permits.

Afterwards, the interface details should show regulatory-domain and the correct country on every radio, with the current frequency inside the ranges listed in Wireless → Country Info. Then re-run the audit with the same country selected; the finding disappears.

The full MKRouterKit report gives the exact commands for your configuration — with your interface names and subnets filled in, in the order that will not lock you out.

FAQ

I enabled superchannel to use channel 149 or higher on 5 GHz. Is that a problem?

In the EU and many other regions, yes — that range is not available for unlicensed WiFi, regardless of what the hardware can do. Some countries allow it (the United States, for example, under FCC rules). Set the country correctly and use the channels it offers; if your region permits the upper band, regulatory-domain mode will list it.

Won't regulatory-domain mode reduce my range?

It limits transmit power to the legal maximum, which on most MikroTik hardware is close to what the radio does anyway. Clients, especially phones, transmit at far lower power than the access point, so the link is usually limited by the client side; extra AP power mainly increases interference for the neighbours without improving the connection.

The country is set correctly. Doesn't that override superchannel?

No. In superchannel mode the country setting is ignored for frequency and power limits. The two settings must go together: regulatory-domain mode and the right country.