Commits
Balaji Pothunoori committed 81d5439da84
cfg80211: average ack rssi support for data frames
Average ack rssi will be given to userspace via NL80211 interface
if firmware is capable. Userspace tool ‘iw’ can process this
information and give the output as one of the fields in
‘iw dev wlanX station dump’.
Example output :
localhost ~ #iw dev wlan-5000mhz station dump Station
34:f3:9a:aa:3b:29 (on wlan-5000mhz)
inactive time: 5370 ms
rx bytes: 85321
rx packets: 576
tx bytes: 14225
tx packets: 71
tx retries: 0
tx failed: 2
beacon loss: 0
rx drop misc: 0
signal: -54 dBm
signal avg: -53 dBm
tx bitrate: 866.7 MBit/s VHT-MCS 9 80MHz short GI VHT-NSS 2
rx bitrate: 866.7 MBit/s VHT-MCS 9 80MHz short GI VHT-NSS 2
avg ack signal: -56 dBm
authorized: yes
authenticated: yes
associated: yes
preamble: short
WMM/WME: yes
MFP: no
TDLS peer: no
DTIM period: 2
beacon interval:100
short preamble: yes
short slot time:yes
connected time: 203 seconds
Main use case is to measure the signal strength of a connected station
to AP. Data packet transmit rates and bandwidth used by station can vary
a lot even if the station is at fixed location, especially if the rates
used are multi stream(2stream, 3stream) rates with different bandwidth(20/40/80 Mhz).
These multi stream rates are sensitive and station can use different transmit power
for each of the rate and bandwidth combinations. RSSI measured from these RX packets
on AP will be not stable and can vary a lot with in a short time.
Whereas 802.11 ack frames from station are sent relatively at a constant
rate (6/12/24 Mbps) with constant bandwidth(20 Mhz).
So average rssi of the ack packets is good and more accurate.
Signed-off-by: Balaji Pothunoori <bpothuno@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>