160MHz on Cudy X6 and conflicting iw reg get data

Installing and Using OpenWrt Network and Wireless Configuration
1

I was playing with 160Mhz width on OpenWrt 22.03.02. After playing with it for some time and getting start_dfs_cac() failed, -1, I decided to check data. And it looks quite strange

iw reg get
global
country US: DFS-FCC
        (902 - 904 @ 2), (N/A, 30), (N/A)
        (904 - 920 @ 16), (N/A, 30), (N/A)
        (920 - 928 @ 8), (N/A, 30), (N/A)
        (2400 - 2472 @ 40), (N/A, 30), (N/A)
        (5150 - 5250 @ 80), (N/A, 23), (N/A), AUTO-BW
        (5250 - 5350 @ 80), (N/A, 24), (0 ms), DFS, AUTO-BW
        (5470 - 5730 @ 160), (N/A, 24), (0 ms), DFS
        (5730 - 5850 @ 80), (N/A, 30), (N/A), AUTO-BW
        (5850 - 5895 @ 40), (N/A, 27), (N/A), NO-OUTDOOR, AUTO-BW, PASSIVE-SCAN
        (5925 - 7125 @ 320), (N/A, 12), (N/A), NO-OUTDOOR, PASSIVE-SCAN
        (57240 - 71000 @ 2160), (N/A, 40), (N/A)

If I get it right, only range 5470 - 5730 supports 160MHz and it looks like I have to set channel 96 in router. But I cannot set such channel.

On other side I have this:

iw phy1 info
Frequencies:
                        * 5180 MHz [36] (23.0 dBm)
                        * 5200 MHz [40] (23.0 dBm)
                        * 5220 MHz [44] (23.0 dBm)
                        * 5240 MHz [48] (23.0 dBm)
                        * 5260 MHz [52] (24.0 dBm) (radar detection)
                        * 5280 MHz [56] (24.0 dBm) (radar detection)
                        * 5300 MHz [60] (24.0 dBm) (radar detection)
                        * 5320 MHz [64] (24.0 dBm) (radar detection)
                        * 5500 MHz [100] (24.0 dBm) (radar detection)
                        * 5520 MHz [104] (24.0 dBm) (radar detection)
                        * 5540 MHz [108] (24.0 dBm) (radar detection)
                        * 5560 MHz [112] (24.0 dBm) (radar detection)
                        * 5580 MHz [116] (24.0 dBm) (radar detection)
                        * 5600 MHz [120] (24.0 dBm) (radar detection)
                        * 5620 MHz [124] (24.0 dBm) (radar detection)
                        * 5640 MHz [128] (24.0 dBm) (radar detection)
                        * 5660 MHz [132] (24.0 dBm) (radar detection)
                        * 5680 MHz [136] (24.0 dBm) (radar detection)
                        * 5700 MHz [140] (24.0 dBm) (radar detection)
                        * 5720 MHz [144] (24.0 dBm) (radar detection)
                        * 5745 MHz [149] (24.0 dBm)
                        * 5765 MHz [153] (24.0 dBm)
                        * 5785 MHz [157] (24.0 dBm)
                        * 5805 MHz [161] (24.0 dBm)
                        * 5825 MHz [165] (24.0 dBm)
                        * 5845 MHz [169] (24.0 dBm) (no IR)
                        * 5865 MHz [173] (24.0 dBm) (no IR)

I don't see 5470 MHz. Is it bug in data or am I missing something?

Vlad

2

Are you sure your radio supports HE160? I know lots of people try VHT160 on MediaTek 802.11ac radios but it doesn't work nor is it supported, despite being advertised. Might be the same on MT7915, AFAIK it's an early 802.11ax generation. Those often don't support the full spec feature set.

3

Playing with the region setting might help. Not all frequencies are allowed in all countries, and the default 00 code isn't a workaround.

4

that radio do not support 160 mhz

2 Likes
5

DBDC mode in X6 and other AX1800 mt7915d devices do not support 160Mhz operations .There is even pull that removes it from sight.

2 Likes
6

Ok, thank you @anon4457646 and @nicefile much for clarification. Does this device support AX mode? From patch it looks like it removed 160MHz but not AX mode.

7

Yes ax 80 is possible. MIMO is limited to 2x2 in all DBDC modes since the four DSP chains in the MT7915 are split between the two bands.

ax 160 requires dedicating two DSPs per RF chain (all 4 used for 2x2 ax 160 on 5 GHz) thus it is not supported in a DBDC configuration.

It should also be noted that iw reg get is always going to report fully what the regulations allow in your country--not what your particular hardware can run.

2 Likes
8

This topic was automatically closed 10 days after the last reply. New replies are no longer allowed.