Hi, I did some testing with the latest version of the ath9k_htc drivers in 3.9.0-rc8-wl which already has the patch https://patchwork.kernel.org/patch/2177921/ ....and the results are much better.
Can you point out the AR9285 RX descriptor contents relating to antenna configuration? Regards, On Friday 26 April 2013 08:08 PM, Adrian Chadd wrote: > There's some driver work that Felix and others did or are talking > about, which tidy up the RSSI measurement. > > There's also the antenna diversity behaviour; depending upon which > antenna is used, there's a few dB difference (same as the AR9285.) > > I'm sorry, I can't work on it any more than that. I can point out what > the AR9285 RX descriptor contents are relating to antenna > configuration; that way someone can add that to ath9k and possibly > link antenna selection / configuration to the RSSI differences. But I > can't do the legwork, sorry. > > > > > Adrian > > On 26 April 2013 06:56, Trevor Cullen <[email protected]> wrote: >> This issue totally destroyed deployment of DNUA-93F (AR9271) USB Wifi in a >> similar application. Now use Realtek with very stable results. >> >> But there is history. >> >> See https://patchwork.kernel.org/patch/2177921/ and attached. >> >> Trevor >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]] On Behalf Of Harshal Vora >> Sent: 26 April 2013 11:43 >> To: Adrian Chadd >> Cc: [email protected] >> Subject: Re: [ath9k-devel] varying RSSI values with ath9k_htc drivers for >> TL-WN721N USB wifi adapter. >> >> On Friday 26 April 2013 01:39 AM, Adrian Chadd wrote: >>> Have you actually verified that the output power of those devices is >>> actually constant? >>> >>> >>> >>> Adrian >>> >>> On 25 April 2013 07:08, Harshal Vora <[email protected]> wrote: >>>> Hi, >>>> >>>> I are trying to achieve approximate location detection (room level >>>> granularity) based on RSSI. >>>> I am using TP-LINK TL-WN721N USB wifi adapter which require ath9k_htc >>>> drivers. >>>> Operating system: Ubuntu 12:04 LTS. >>>> >>>> The RSSI values recorded vary a lot, even when the transmitter >>>> (iPhone 5 and sony xPeria and other phones) and the receiver are left >>>> untouched at the same location. >>>> >>>> There is a difference of almost 15 to 20 dbm in the readings. >>>> Sometimes it is in the range of -40 to -50dbm .. sometimes -50 to >>>> -60dbm >>>> >>>> Also sometimes the RSSI values are always between -75 to -85 dbm no >>>> matter how short or long the distance is between the two devices. >>>> >>>> I am using airmon-ng to set the device in monitor mode and tshark to >> sniff. >>>> I have tried with the drivers that come with ubuntu 12.04, with >>>> compat-wireless 3.6.8-1 as well as compat-drivers 3.8.3-2 >>>> >>>> The todo list on >>>> http://wireless.kernel.org/en/users/Drivers/ath9k_htc#TODO >>>> mentions >>>> Low RSSI issue for UB91/94. >>>> >>>> Should this be a concern? >>>> >>>> >>>> Regards, >>>> >>>> _______________________________________________ >>>> ath9k-devel mailing list >>>> [email protected] >>>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >> >> Hi, >> >> I have a MAC laptop which has inbuilt broadcom BCM 4331 chipset running on >> b43 drivers. >> >> I put the iPhone in charging and it is always unlocked and on the wifi >> settings page which displays available networks. >> From what I understand, iPhone goes in power saver mode only when locked. >> The readings on bcm4331 are much stable as compared to the wn721n usb >> adapter. >> On broadcom, the dbm values differ mostly by 3-4 dbm and sometimes I see a >> spike with a difference of 7-8dbm. >> On the other hand the dbm values using ath9k_htc drivers differ by 10-15dbm. >> >> I have also tested with a locked iPhone to get similar results. >> >> In another setup, I connected one wn721n chipset to hackberry and another to >> my laptop. >> Again I took two sets of readings with transmitter as wn721n on hackberry >> and receiver as bcm4331 in the first run and receiver as wn721n on my mac in >> the second run. >> Again similar observaions as the experiment with iPhone as transmitter. >> >> How can I measure the output transmission power? I deployed the ath9k_htc >> drivers in debug mode with value 0xffffffff. But cannot get any relevant >> information from debugfs. >> When I do ifconfig, it says power management off. >> When I run sudo iwconfig "dev" txpower "value", it returns an error. >> >> I have taken a lot of different sets of readings for ath9k_htc, and >> relatively the readings are correct. i.e. the dbm values will change as the >> distance between the transmitter and receiver changes. But sometimes the dbm >> values remain in a particular range say -75dbm to -85dbm no matter how near >> or far the transmitter is from the receiver. >> >> Regards, >> _______________________________________________ >> ath9k-devel mailing list >> [email protected] >> https://lists.ath9k.org/mailman/listinfo/ath9k-devel _______________________________________________ ath9k-devel mailing list [email protected] https://lists.ath9k.org/mailman/listinfo/ath9k-devel
