ASUS RT-AX88U

Specs

Generation: WiFi 6
Bands: 2.4 GHz + 5 GHz
Transmit power (preset): 21 dBm
Antenna gain (preset): 4 dBi

Transmit power and antenna gain are informed presets, not datasheet values. Consumer WiFi vendors publish PHY rates, not conducted power, so these two figures come from a documented, deliberately conservative rule instead of a spec sheet — they exist to keep the Coverage Mapper and Channel Advisor honest, not to describe this exact unit down to the milliwatt.

Band capabilities

2.4 GHzUp to about 100 Mbps at close range, real-world — well under the number printed on the box.
5 GHzUp to about 600 Mbps at close range, real-world — well under the number printed on the box.

No 6 GHz radio on this model. 5 GHz is the fastest band it has.

Channel guidance

ASUS RT-AX88U (WiFi 6) — using the Conservative worldwide set channel rules.

For a typical household on this hardware, run through the exact same Channel Advisor logic every real visitor gets. Answer five questions yourself for guidance tuned to your own neighbours and country.

2.4 GHzRange band

6 channel20 MHz wide

A moderate amount of company on this band. 1/6/11 are the only channels that do not overlap each other; channel 6 is the middle one and is less crowded than the factory-default ends.

Use 20 MHz here no matter what your router offers: 40 MHz on 2.4 GHz eats two thirds of the band and leaves no clean channel for anyone, including you. The channel itself is an educated guess — we cannot scan your neighbours from a web page, so if the change does not help, try the other channels in the set. A real scan is what the desktop scanner is for.

5 GHzEveryday band

44 channel80 MHz wide

Moderate company on 5 GHz, and your regulatory domain does not open the upper non-DFS block (UNII-3), so there is no second non-DFS home to move to. Channel 44 is an off-center pick inside the only non-DFS range here (36/40/44/48) — still no radar-vacate risk, just not guaranteed to be quiet at this density.

With this much company on the band and only one non-DFS range to share, a DFS channel may genuinely be quieter even though it carries a radar-vacate risk — worth trying if this one stays congested.

These are recommendations, not measurements. The widths and the band advice are physics and hold everywhere. The channel numbers are an educated guess built from how many networks you told us you can see — we cannot scan your neighbours from a web page, because no browser is allowed to. If a change does not help, try the other channels in the same set; nothing here can damage anything, and every one of these settings is reversible.

How to change this on your ASUS (RT, ROG, ZenWiFi)

Where to sign in: http://router.asus.com — or 192.168.1.1 — or the ASUS Router app

Menu names are shown as they appear in the router’s English interface — your router may show them in your own language.

Open http://router.asus.com in a browser and sign in with the router admin account.
In the left menu choose Wireless (under Advanced Settings), and stay on the General tab.
If “Smart Connect” is enabled at the top of the page, switch it off so each band can be tuned on its own.
Choose the band in the Frequency / Band dropdown, then set Control Channel to the recommended channel and Channel Bandwidth to the recommended width.
Click Apply at the bottom and wait for the router to finish reloading before reconnecting.
On a ZenWiFi mesh set, do this on the main node only — the satellites follow it.

Menu names drift between firmware versions. If a label here does not match what you see, look for the nearest equivalent — the two fields you want are always called something close to “Channel” and “Channel Width” (or “Bandwidth”).

Placement notes

A higher-gain antenna array reaches further in open space, but that same gain focuses the signal into a flatter pattern — vertical coverage (the floor above or below) can be worse than a lower-gain router in the same spot.
Two radios, 2.4 and 5 GHz — put the router where 5 GHz can reach the rooms you actually use; 2.4 GHz will cover the rest of the home regardless.