[RT-AC68U] Weak WiFi performance in repeater mode

[Cygnusx3]

Hey guys,

I have a problem with the wifi output of my RT-AC68U in repeater mode, which is connected to the GT-AX11000. The GT-AX is running the latest ASUS firmware and the RT-AC the latest Merlin firmware, older/official firmware doesn't change anything.

The RT-AC68U is sitting one floor above the GT-AX and it receives 877.5Mbps to 1053Mbps @-65dBm via the 5GHz AC band, though I know those numbers are just theoretical.
If I connect to the RT-AC68U with an ethernet cable I am getting the full 450Mbps of my internet connection bandwidth, but I am 'only' getting 140Mbps over WiFi with a PCE-AC68U network card about 6 meters (20 feet) away, without any walls/obsticles in between.
For comparison: I got the full 450Mbps with my old setup (RT-AC68U in ap-mode to modem, same WiFi-card) on the same floor, with a brick wall and two huge closets between them, 5 meters (~16 feet) apart. The network card showed a theoretical speed of 877.5Mbps, so the same as the RT-AC68U currently shows in repeater mode.

Is the RT-AC68U only able to send 140-150Mbps over 6 meters via the 5GHz band in repeater mode, if it receives at least real 450Mbps? My other devices (laptop and smartphone) are getting even less than that (around 100Mbps) if I am right next to the 'repeater'. And range shouldn't matter for the PCE-AC68U, since I got better results with my old setup under worse circumstances.

On another note: My WiFi-card and the RT-AC68U cannot find/see the second 5GHz AC-band of the GT-AX11000 (channels 100-140). That's the dedicated 'gaming' band with better performance than the first 5GHz band (channels 36-64) - I already tried to set the channel manually without success... Every other device can see the second band.
Would it be better if I open another thread in the AX-forum?

Other:
- LAN is no option, only tried it for testing
- Region is EU (regarding channels)

Thanks for your help

 

[roguetr]

Repeater speeds will generally be less than half the connection speed. If everything checks out in AP mode it may just be that

Using the media bridge/wifi backhaul option may be a better option. What your wanting to do is extend your wifi rather than repeat it. There's some decent dualband wireless extenders around.

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[Klueless]

Repeater speeds will generally be less than half the connection speed.

Good point. To elaborate let's say the client connects to the repeater @ 5 GHz and the repeater connects to the router @ 5 GHz. Client sends to repeater, repeater effectively shuts down its radio so it can relay the data to the router. Speed is "halved"

Now let's have the client talk to the repeater @ 2.4 GHz while the repeater talks to the router @ 5 GHz. Client sends, there is no shut down because the repeater is sending to the router over the other radio so the client can send, send and send.

Now we have a new problem; 2.4 GHz itself will limit your speeds. Guess that goes towards explaining why tri-band mesh and extenders have become available.

My WiFi-card and the RT-AC68U cannot find/see the second 5GHz AC-band

I've a 68U, US model, and I'm not seeing support for channels 100-140?

 

[roguetr]

Good point. To elaborate let's say the client connects to the repeater @ 5 GHz and the repeater connects to the router @ 5 GHz. Client sends to repeater, repeater effectively shuts down its radio so it can relay the data to the router. Speed is "halved"

Now let's have the client talk to the repeater @ 2.4 GHz while the repeater talks to the router @ 5 GHz. Client sends, there is no shut down because the repeater is sending to the router over the other radio so the client can send, send and send.

Now we have a new problem; 2.4 GHz itself will limit your speeds. Guess that goes towards explaining why tri-band mesh and extenders have become available.

I've a 68U, US model, and I'm not seeing support for channels 100-140?

I haven't tried but I'm assuming with the tri band routers like my ac5300, you can dedicate one 5Ghz band to backhaul whilst still advertising the other.

Sent from my MI 5 using Tapatalk

 

[Cygnusx3]

Thanks for your replies, really appreciate it!

Now let's have the client talk to the repeater @ 2.4 GHz while the repeater talks to the router @ 5 GHz. Client sends, there is no shut down because the repeater is sending to the router over the other radio so the client can send, send and send.

That would explain why I get the same speed (~120Mbps) @2.4GHz with the 'repeater', even though 5GHz is usually way faster.

Using the media bridge/wifi backhaul option may be a better option. What your wanting to do is extend your wifi rather than repeat it. There's some decent dualband wireless extenders around.

Using the RT-AC in media bridge mode would definitely be the best way to go regarding speed, but LAN is unfortunately no option.
I could buy another router/extender, connect it to the GT-AX11000 as a media bridge over the 5GHz band and use an ethernet cable to connect the new device to the RT-AC68U as an access point.
Would the RT-AC68U as an ap send the full 450+Mbps it gets via LAN, or do I have to expect (significantly) lower speeds?

I've a 68U, US model, and I'm not seeing support for channels 100-140

Just tested my network card (EU model) with different channels and it looks like it doesn't support DFS, so basically any channel above 48. Any idea how I can remove the restrictions?

 

[roguetr]

What you've suggested utilises the fastest options you have available for what you want to do.

If you wanted to consolidate, you could get a tri band extender. One device for 5Ghz backhaul and wireless advertisement.

You're total throughput is all going to depend on maintaining optimal wireless connectivity. You just want to ensure your wireless backhaul has a strong connection and does not become a bottleneck.

Maintaining connections strong enough to utilise the entire 450Mbps may be difficult but definitely not impossible. If you're lucky it will just work. All connections will have to be AC.

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