I just purchased an Alfa USB wifi network adapter with the MediaTek 7610U chipset and although it's a great USB adapter one of it's major selling points is supposed to be its power. But I can't even get it to the US standard of 100mW because OpenWrt will not allow me to set anything above 18dBm (63mW) in wireless AC mode and a completely unusable 4 dBm (2mW!!!) in wireless N mode. This thing is supposed to be capable of the 100mW US maximum (I thought), why such the disparity? Have I configured something incorrectly or is it a bug?
There are 3 USB wifi adapters attached to this Pi (2X Alfa AWUS036ACM MT7612U chipset & 1X Alfa AWUS036ACHM MT7610U chipset) and only the adapter with the MT7610U chipset is having issues with tx power. All devices are powered by a 3amp USB powered hub(s) and the issue persists whether directly connected to the Pi or through a USB hub. The issue persists if the MT7610U adapter is the only device attached to the Pi. When I'm sitting next to it tx speeds are a little low (there's room for adjustment) but that's not my major concern at the moment.
I've modified the etc/wireless/config by changing the 18dBm to 20/22/30dBm, whatever, it has no bearing on the transmit power even after a network reload and/or system reboot. I'm under the impression this is actually hardcoded into the firmware so editing that particular setting is useless? How do I correct this?
Here is what iwinfo tells me. Below that is the /tmp/run/hostapd-phy3.conf for the MT7610U adapter.
wlan3 ESSID: "YourWifiPasswordSucks" Access Point: 00:C0:CA:XX:XX:XX Mode: Master Channel: 48 (5.240 GHz) Center Channel 1: 42 2: unknown Tx-Power: 18 dBm Link Quality: 70/70 Signal: -36 dBm Noise: unknown Bit Rate: 292.5 MBit/s Encryption: WPA2 PSK (CCMP) Type: nl80211 HW Mode(s): 802.11nac Hardware: unknown [Generic MAC80211] TX power offset: unknown Frequency offset: unknown Supports VAPs: yes PHY name: phy3 ------------------------------------------------------------------------------------ driver=nl80211 logger_syslog=127 logger_syslog_level=2 logger_stdout=127 logger_stdout_level=2 country_code=US ieee80211d=1 ieee80211h=1 hw_mode=a beacon_int=100 dtim_period=2 channel=48 chanlist=48 noscan=1 tx_queue_data2_burst=2.0 ieee80211n=1 ht_coex=0 ht_capab=[HT40-][SHORT-GI-20][SHORT-GI-40][RX-STBC1] ieee80211ac=1 vht_oper_chwidth=1 vht_oper_centr_freq_seg0_idx=42 vht_capab=[SHORT-GI-80][RX-ANTENNA-PATTERN][TX-ANTENNA-PATTERN][RX-STBC-1][MAX-A-MPDU-LEN-EXP3] radio_config_id=b9921f8c8f997ecd6fc45f6f3e2f880f interface=wlan3 ctrl_interface=/var/run/hostapd bss_load_update_period=60 chan_util_avg_period=600 disassoc_low_ack=1 skip_inactivity_poll=0 preamble=1 wmm_enabled=1 ignore_broadcast_ssid=0 uapsd_advertisement_enabled=1 utf8_ssid=1 multi_ap=0 wpa_passphrase=XXXXXX wpa_psk_file=/var/run/hostapd-wlan3.psk auth_algs=1 wpa=2 wpa_pairwise=CCMP ssid=YourWifiPasswordSucks wpa_disable_eapol_key_retries=0 wpa_key_mgmt=WPA-PSK okc=0 disable_pmksa_caching=1 dynamic_vlan=0 vlan_naming=1 vlan_file=/var/run/hostapd-wlan3.vlan config_id=1fac86c578ade03c5d2bd07a4c3516aa bssid=00:c0:ca:XX:XX:XX