How to enable dual carrier modulation (DCM) for WiFi 9098 chip?

[hieule]

Hi!

So I learn that WiFi6 802.11ax provides couple of means to improve coverage, including dual carrier modulation (DCM). In this mode, signal is carried in more than one frequency sub-band. In other words, signal is repeated in frequency domain. That way, the received signals have more chance to be decoded correctly.

The question is how to properly enable that feature for 9098 chip. I dig the documents, but could not find the answer. In one of the document, I noticed DCM is not listed under 802.11ax features, so maybe it's not supported. Also, is this DCM applicable for both AP and STA interfaces?

I hope someone could help.

Best,

HL

[shaun_wu]

Hello @hieule 

Can you share driver version?

Best Regards

Shaun

[hieule]

`mlanutl` returns:

Version string received: PCIE9098--17.68.1.p136.32-MXM5X17366.p32-GPL-(FP68)

[shaun_wu]

Hello @hieule 

DCM should be enabled in default. We also provide commend to check statues:

range_ext

    This command is used to config range extension mode.

    Usage:

        mlanutl mlanX/uapX range_ext [mode]

where the parameter is:

        [mode]:

            0:  Default Mode(Auto Rate)

            1:  HE ER+DCM Mode

            2:  Legacy Mode(1 Mbps Rate)

    Example:

        mlanutl mlan0 range_ext      : get range extension mode

mlanutl mlan0 range_ext 1    : set range extension mode to HE ER+DCM mode

Best Regards

Shaun

[hieule]

Thank you very much!
Just tried out but no success:
```
admin@devboard6:~$ mlanutl mlan0 11axcfg
11axcfg: len=55
02 ff 00 1a 00 23 01 08 00 02 00 08 04 70 72 c9
fd 01 a0 0a 00 3d 00 fa ff fa ff a1 ff 03 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00

admin@devboard6:~$ mlanutl mlan0 range_ext
mlanutl: Bad address
mlanutl: range_ext fail
```

[hieule]

@shaun_wu Any feedback?