Ar750-ext and rtl8187 and DFS 5GH

Hi there. Thank your for awesome router.
And I have some questions.
Is it possible add support of rtl8187 USB adapters to firmware or how I can compile it on the router?
And the second question is how connect to DFS 5GH wifi networks? That is my home network on rt87u.
Which country should I used for wifi settings.

Realtek drivers are available for Linux – en:users:drivers:rtl8187 [Linux Wireless] Drivers should be available through the kmod-rtl8187 package.

Many consider the Realtek USB units to be relatively unreliable under Linux. Regrettably, there isn’t a “good” 802.11ac USB dongle for Linux that I am aware of.

DFS is a standard feature of any compliant 802.11 implementation. You do not need to do anything “special” in connecting to an AP that operates on 5 GHz.

Your country code must be that of the country in which you are operating the device.

packages are in the repo…

opkg list kmod-rtl*
kmod-rtl8187 - 4.9.109+2017-11-01-9 - Realtek Drivers for RTL818x devices (RTL8187 USB)
kmod-rtlwifi-usb - 4.9.109+2017-11-01-9 - Realtek common driver part (USB support)

Word to the wise - that’s a pretty old chipset - 802.11 b/g - using this can adversely impact your WLAN and neighbors on the same channel

Maybe - depend on your Asus RT-AC87U and what it’s capable of - some HW revs can do DFS…

From a client perspective - iw is definitely your friend here… you can do iw list to see how the 5GHz driver is built and configured… if you see channels with something like this… client is ok, but AP is not…

		* 5260 MHz [52] (22.0 dBm) (no IR, radar detection)
		* 5280 MHz [56] (22.0 dBm) (no IR, radar detection)
		* 5300 MHz [60] (22.0 dBm) (no IR, radar detection)
		* 5320 MHz [64] (22.0 dBm) (no IR, radar detection)

Getting/Setting region… again - iw is your friend…

# iw reg get
global
country US: DFS-FCC
(2402 - 2472 @ 40), (N/A, 30), (N/A)
(5170 - 5250 @ 80), (N/A, 23), (N/A), AUTO-BW
(5250 - 5330 @ 80), (N/A, 23), (0 ms), DFS, AUTO-BW
(5490 - 5730 @ 160), (N/A, 23), (0 ms), DFS
(5735 - 5835 @ 80), (N/A, 30), (N/A)
(57240 - 63720 @ 2160), (N/A, 40), (N/A)

phy#0
country US: DFS-FCC
(2402 - 2472 @ 40), (N/A, 30), (N/A)
(5170 - 5250 @ 80), (N/A, 23), (N/A), AUTO-BW
(5250 - 5330 @ 80), (N/A, 23), (0 ms), DFS, AUTO-BW
(5490 - 5730 @ 160), (N/A, 23), (0 ms), DFS
(5735 - 5835 @ 80), (N/A, 30), (N/A)
(57240 - 63720 @ 2160), (N/A, 40), (N/A)

iw reg set might be available… do the right thing and use the region that the AP is physically located - DFS is there for a very good reason…

I’ve had decent luck with realtek USB under linux as a client sta - sometimes one has to get creative with chipsets that are not mainline… but I do agree in principal that 11ac drivers under linux can be problematic when diving deep into the wifi protocol stack - which is a sad point since 11ac has been around now for a number of years - I put the blame on the chipset vendors there

thank you sfx2000 i had found and install drivers for 8187.
I have special usb adapter for long range the best result I have got is 5mile wifi connection. I use it sometimes when the WiFi available only on hotel lobby (most Egyptians hotels)
Will try iw to find why portable router can’t connect by 5GHZ to my home router.