Hi everyone,

Is there a way to force MCS7 (64-QAM) on 802.11n for 5G bands in routerOS? I'm performing an RF experiment and need to force MCS7 regardless of the noise environment. If MCS7 cannot be achieved, the signal throughput should drop off to 0Mbps. I want to prevent the router from increasing TX power or going to a lower MCS rate to maintain connectivity. I was able to limit the TX power in RouterOS but am struggling with locking the rate.

To perform the experiment, I'm using two RB4011iGS+5HacQ2HnD-IN routers. I've set them up as an AP bridge. Even with only 54mbps, MCS7 Supported, 5G-OnlyN, and MCS7 Basic setting boxes in RouterOS selected I still see lower modulations appear on my signal analyzer (I've coupled the chosen 5200MHz signal off the antenna output).

Any help would be greatly appreciated.

Even with only 54mbps, MCS7 Supported, 5G-OnlyN, and MCS7 Basic setting boxes in RouterOS selected I still see lower modulations appear

What did you set?

Basic rate on MCS7 is a high value.

Initial connection requests from clients and corresponding handshakes for connection are always at 6 Mbps, this is independent of Basic rates and supported rates set.
(Unless there is some device around transmitting in 802.11b protocol, then it could drop to 1Mbps)
https://networkengineering.stackexchang ... in-802-11n


Also listen to Ron Touw (50:00 onwards, till 53:00 ) https://www.youtube.com/watch?v=LL9qu1dC8eg

I have attached our current wireless settings for the wireless interface wlan1 (The Wireless QCA9984 transceiver).

I see the transmission switching between 16-QAM (Present roughly ~90% of the time) and 64-QAM (Present roughly 10% of the time). It seems that RouterOS is not forcing the rate as the settings suggest under HT MCS. Any suggestions?

Thank you for the help.

Don't know how this is implemented in RouterOS.
Maybe we should ask Uldis (@Mikrotik) for details.

See page 54 till page 57 in https://mum.mikrotik.com/presentations/ZA13/uldis.pdf