BPI-MT7615 how to enable concurrent dual-band operation

How do I create two separate access points on my BPI-MT7615 wireless adapter: one on 2.4GHz and the other on 5GHz? I can successfully create a 2.4GHz AP or a 5GHz AP separately using hostapd, however apparently it does not support creating multiple access points on different channels.

I would really appreciate any guidance.

echo 1 > /sys/kernel/debug/ieee80211/phy0/mt76/dbdc
1 Like

Ok, so I enabled DBDC, however I am still unable to bring the two access points up. I have tried creating two virtual managed interfaces like this:

iw dev wlan0 interface add wlan0_sub1 type managed addr 12:34:56:78:ab:cc
iw dev wlan0 interface add wlan0_sub2 type managed addr 12:34:56:78:ab:ce 

and starting hostapd with two config files for the two bands:

hostapd -dd /etc/hostapd1.conf /etc/hostapd2.conf
hostapd1.conf
#
# 2.4 GHz AP configuration
#

ssid=xxxxx
interface=wlan0_sub1
bss=wlan0_sub
hw_mode=g
channel=9
bridge=br0
driver=nl80211

logger_syslog=0
logger_syslog_level=0
wmm_enabled=1
wpa=2
preamble=1

wpa_psk=XX
wpa_passphrase=XX
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP
auth_algs=1
macaddr_acl=0

## IEEE 802.11n
ieee80211n=1
ht_capab=[SHORT-GI-20][SHORT-GI-40][HT40+]
country_code=XX
ieee80211d=1
hostapd2.conf
#
# 5 GHz AP configuration
#

ssid=xxxxx2
interface=wlan0_sub2
bss=wlan0_sub2
hw_mode=a
channel=40
bridge=br0
driver=nl80211

logger_syslog=0
logger_syslog_level=0
wmm_enabled=1
wpa=2
preamble=1

wpa_psk=XX
wpa_passphrase=XX
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP
auth_algs=1
macaddr_acl=0

## IEEE 802.11n
ieee80211n=1
ht_capab=[SHORT-GI-20][SHORT-GI-40][HT40+]
country_code=XX
ieee80211d=1

Which gives the following error:

Failed to create interface wlan0_sub1: -23 (Too many open files in system)
Try to remove and re-create wlan0_sub1
nl80211: Remove interface ifindex=133
nl80211: if_indices[16]: 9(134) 134(-1)
nl80211: if_indices[16]: 9(134) 134(-1)
nl80211: if_indices[16]: 9(133)
nl80211: if_indices[16]:
nl80211: Create interface iftype 3 (AP)
Failed to create interface wlan0_sub1: -19 (No such device)
Failed to add BSS (BSSID=12:34:56:78:ab:cc)

I have also tried to simply use the main interface (wlan0) however this also fails.

Am I doing something wrong? For some reason, I can’t find any examples on how to host two separate access points on two separate bands or even a single one with automatic band selection.

Try to start one hostapd process on each interface (without iw before) and show log for both