TP-Link TL-WR902AC v3 19.07.0 5GHz access point not showing up with both master + client

Installing and Using OpenWrt
1

I have flashed ,my TP-Link TL-WR902AC v3 with the latest 19.07.0 firmware. It works and when I setup a 2.4Ghz AP(master mode) + 5Ghz AP (master mode) with no clients connected, Both the 2.4Ghz and 5Ghz show up in client list.

However, If I scan + setup the router to connect to a 5Ghz access point to share the internet from it, it connects but than my 5ghz access point disappear's and only the 2.4Ghz access point only shows. I can connect to the 2.4Ghz but I can't see the 5ghz access point (master mode) on any of my clients. If I remove the client, it shows. Any ideas on how to make it work on the 5ghz client + ap master mode?

root@OpenWrt:/tmp/log# cat /etc/config/wireless

config wifi-device 'radio0'
        option type 'mac80211'
        option hwmode '11g'
        option path 'platform/10300000.wmac'
        option channel '1'
        option htmode 'HT20'

config wifi-iface 'default_radio0'
        option device 'radio0'
        option network 'lan'
        option mode 'ap'
        option ssid 'OpenWrt'
        option wpa_disable_eapol_key_retries '1'
        option key 'test1234'
        option encryption 'psk2'

config wifi-device 'radio1'
        option type 'mac80211'
        option hwmode '11a'
        option path 'pci0000:00/0000:00:00.0/0000:01:00.0'
        option htmode 'VHT80'
        option beacon_int '75'
        option legacy_rates '0'
        option channel '36'

config wifi-iface 'wifinet3'
        option ssid 'OpenWrt_5g'
        option device 'radio1'
        option mode 'ap'
        option network 'lan'
        option key 'test1234'
        option wpa_disable_eapol_key_retries '1'
        option encryption 'psk2'

config wifi-iface 'wifinet2'
        option ssid 'wireless2'
        option device 'radio1'
        option mode 'sta'
        option key 'test1234'
        option network 'wwan'
        option encryption 'psk2'
2

I am not familiar with this hardware, but I guess the following information might help with a resolution.

Please post the output of

iw dev
iw phy | grep -A3 combinations

with the router's wwan connected to the 5Ghz access point.

3

This is known and expected behaviour. The 5GHz AP must use the same channel as the main router, so it has to wait for the main router to be available.

4

Thanks @eduperez , if I changed my master 5Ghz radio channel to the same channel as the 5Ghz AP channel that's my router, it both works at the same time. I did however find out that if the routers 5ghz router is channel 165, the master 5Ghz radio wouldn't work. If I changed my routers 5ghz to channel 36 AND change my master 5ghz radio to channel 36, my master 5Ghz radio now shows up.

1 Like
5

Hi, I bumped into the exact same problem as yours, even the device model and version are the same.
May I know how you solved this problem please? I tried to follow this thread, but still not sure the procedures.

(1) So when I use MediaTek MT7610E 802.11nac (radio1, for 5g) to connect to the hotel wifi as a client, my phone cannot see my "OpenWrt-5g" in the wifi list at all, but can only see "OpenWrt-2.4g" there, and is able to connect to it and access Internet normally.

(2) However, when I use MediaTek MT76x8 802.11bgn (radio0, for 2.4g) to connect to the hotel wifi as a client, my phone can see both "OpenWrt-2.4g" and "OpenWrt-5g", and connecting to either works well.

@eduperez Also, you mentioned it's the expected behavior, would you mind elaborating on this please? Do you mean that my case (1) is the normal expected behavior that once? but why (2) is different?

Many thanks.

6

The "expected behavior" I commented happens before your router connects to the hotel network: your router needs to scan all channels, trying to connect to the hotel network, and cannot stay fixed on any channel, until it connects to the network.

Once the router has connected, then it can act both as an AP and a STA, and your devices can connect to the router. So, as you are in a situation where the router has already connected, I would say (2) is the expected behavior. The (1) situation may happen when the wifi chipset does not support AP+STA mode, or perhaps because of a missconfiguration, but it is not the expected behavior.