[ath9k-devel] varying RSSI values with ath9k_htc drivers for TL-WN721N USB wifi adapter.

[ath9k-devel] varying RSSI values with ath9k_htc drivers for TL-WN721N USB wifi adapter.

[Trevor Cullen]

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: ath9k-devel-bounces@lists.ath9k.org
[mailto:ath9k-devel-bounces at lists.ath9k.org] On Behalf Of Harshal Vora
Sent: 26 April 2013 11:43
To: Adrian Chadd
Cc: ath9k-devel at lists.ath9k.org
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 <harshal@amideeptech.com> 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
>> ath9k-devel at lists.ath9k.org
>> 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
ath9k-devel at lists.ath9k.org
https://lists.ath9k.org/mailman/listinfo/ath9k-devel
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Subject: [ath9k-devel] [PATCH] ath9k_htc: update RSSI values only when the	device is associated
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[ath9k-devel] varying RSSI values with ath9k_htc drivers for TL-WN721N USB wifi adapter.

[Adrian Chadd]

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 <tcc@innovelec.co.uk> 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: ath9k-devel-bounces at lists.ath9k.org
> [mailto:ath9k-devel-bounces at lists.ath9k.org] On Behalf Of Harshal Vora
> Sent: 26 April 2013 11:43
> To: Adrian Chadd
> Cc: ath9k-devel at lists.ath9k.org
> 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 <harshal@amideeptech.com> 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
>>> ath9k-devel at lists.ath9k.org
>>> 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
> ath9k-devel at lists.ath9k.org
> https://lists.ath9k.org/mailman/listinfo/ath9k-devel

[ath9k-devel] varying RSSI values with ath9k_htc drivers for TL-WN721N USB wifi adapter.

[Harshal Vora]

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 <tcc@innovelec.co.uk> 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: ath9k-devel-bounces at lists.ath9k.org
>> [mailto:ath9k-devel-bounces at lists.ath9k.org] On Behalf Of Harshal Vora
>> Sent: 26 April 2013 11:43
>> To: Adrian Chadd
>> Cc: ath9k-devel at lists.ath9k.org
>> 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 <harshal@amideeptech.com> 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
>>>> ath9k-devel at lists.ath9k.org
>>>> 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
>> ath9k-devel at lists.ath9k.org
>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel

[ath9k-devel] varying RSSI values with ath9k_htc drivers for TL-WN721N USB wifi adapter.

[Harshal Vora]

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] varying RSSI values with ath9k_htc drivers for TL-WN721N USB wifi adapter.

[Adrian Chadd]

Have you actually verified that the output power of those devices is
actually constant?



Adrian

On 25 April 2013 07:08, Harshal Vora <harshal@amideeptech.com> 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
> ath9k-devel at lists.ath9k.org
> https://lists.ath9k.org/mailman/listinfo/ath9k-devel

[ath9k-devel] varying RSSI values with ath9k_htc drivers for TL-WN721N USB wifi adapter.

[Harshal Vora]

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 <harshal@amideeptech.com> 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
>> ath9k-devel at lists.ath9k.org
>> 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,