[ath9k-devel] Radar Detection and DFS status

[ath9k-devel] Radar Detection and DFS status

[mementux]

Hi!

I would like to make an outdoor radio link at 5GHz between my house and one
of my neighbors. Because I live near an airport, I've looked for European in
force regulation regarding radar detection. I've discovered that ETSI has
released a new normative on Dicember 2008 (EN 301 893 v1.5). This normative
requires that WLAN devices with DFS capability must detect pulse width down
to 0.8us across the bands from 5250 to 5350MHz and from 5470 to 5725 MHz;
moreover they must detect staggered Pulse Repetition Frequency (PRF) radars
with 3 PRF value (I don't excactly know what it means).

I have two devices with Atheros 5414 radio module, so I've looked for
support of radar detection (and 802.11h) in madwifi driver. I've seen that
the -dfs branch supports the EN 301 893 v1.4.1 and it implements 802.11h
protocol. Looking into the madwifi-dfs code I've seen that the hardware does
the pulse detection and the driver detects the radar recognizing the pulse
patterns (ath/if_ath_radar.c and ath/if_ath_radar.h).

Because the pulse detection is done in hardware, I suppose that for
detecting pulse width down to 0.8us I need radio modules with newer chipset
like AR9xxx. Is it right? Can't I use my AR5414 radio modules?
So, I've searched in the code of ath9k and mac80211 but I don't find any
implementation of radar detection and 802.11h. Am I wrong? I've read on
http://wireless.kernel.org/en/users/Drivers/ath9k that 802.11h is a feature
of ath9k driver (and consecutively of mac80211, right?).

I there any way to make an outdoor radio link at 5GHz compliant to the
European regulation with Linux? :-)

Thanks,
Albert.
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[ath9k-devel] Radar Detection and DFS status

[Luis R. Rodriguez]

2009/2/11 mementux <mementux@gmail.com>:
> Hi!
>
> I would like to make an outdoor radio link at 5GHz between my house and one
> of my neighbors. Because I live near an airport, I've looked for European in
> force regulation regarding radar detection. I've discovered that ETSI has
> released a new normative on Dicember 2008 (EN 301 893 v1.5). This normative
> requires that WLAN devices with DFS capability must detect pulse width down
> to 0.8us across the bands from 5250 to 5350MHz and from 5470 to 5725 MHz;
> moreover they must detect staggered Pulse Repetition Frequency (PRF) radars
> with 3 PRF value (I don't excactly know what it means).
>
> I have two devices with Atheros 5414 radio module, so I've looked for
> support of radar detection (and 802.11h) in madwifi driver. I've seen that
> the -dfs branch supports the EN 301 893 v1.4.1 and it implements 802.11h
> protocol. Looking into the madwifi-dfs code I've seen that the hardware does
> the pulse detection and the driver detects the radar recognizing the pulse
> patterns (ath/if_ath_radar.c and ath/if_ath_radar.h).
>
> Because the pulse detection is done in hardware, I suppose that for
> detecting pulse width down to 0.8us I need radio modules with newer chipset
> like AR9xxx. Is it right? Can't I use my AR5414 radio modules?
> So, I've searched in the code of ath9k and mac80211 but I don't find any
> implementation of radar detection and 802.11h. Am I wrong? I've read on
> http://wireless.kernel.org/en/users/Drivers/ath9k that 802.11h is a feature
> of ath9k driver (and consecutively of mac80211, right?).
>
> I there any way to make an outdoor radio link at 5GHz compliant to the
> European regulation with Linux? :-)

mac80211 or ath9k does not yet have radar detection support so
therefore no mac80211 driver will allow you to use any beaconing mode
(AP | IBSS | Mesh) mode on DFS channels yet.

Note that not all 5 GHz channels require radar detection though so you
could try using one of the non-DFS channels. Check 'iw list' for that.

ath9k STA should work with DFS but I didn't work on that myself so
will leave someone else to comment on that.

  Luis

Re: [ath9k-devel] Radar Detection and DFS status

[Luis R. Rodriguez]

2009/2/11 mementux <mementux@gmail.com>:
> Hi!
>
> I would like to make an outdoor radio link at 5GHz between my house and one
> of my neighbors. Because I live near an airport, I've looked for European in
> force regulation regarding radar detection. I've discovered that ETSI has
> released a new normative on Dicember 2008 (EN 301 893 v1.5). This normative
> requires that WLAN devices with DFS capability must detect pulse width down
> to 0.8us across the bands from 5250 to 5350MHz and from 5470 to 5725 MHz;
> moreover they must detect staggered Pulse Repetition Frequency (PRF) radars
> with 3 PRF value (I don't excactly know what it means).
>
> I have two devices with Atheros 5414 radio module, so I've looked for
> support of radar detection (and 802.11h) in madwifi driver. I've seen that
> the -dfs branch supports the EN 301 893 v1.4.1 and it implements 802.11h
> protocol. Looking into the madwifi-dfs code I've seen that the hardware does
> the pulse detection and the driver detects the radar recognizing the pulse
> patterns (ath/if_ath_radar.c and ath/if_ath_radar.h).
>
> Because the pulse detection is done in hardware, I suppose that for
> detecting pulse width down to 0.8us I need radio modules with newer chipset
> like AR9xxx. Is it right? Can't I use my AR5414 radio modules?
> So, I've searched in the code of ath9k and mac80211 but I don't find any
> implementation of radar detection and 802.11h. Am I wrong? I've read on
> http://wireless.kernel.org/en/users/Drivers/ath9k that 802.11h is a feature
> of ath9k driver (and consecutively of mac80211, right?).
>
> I there any way to make an outdoor radio link at 5GHz compliant to the
> European regulation with Linux? :-)

mac80211 or ath9k does not yet have radar detection support so
therefore no mac80211 driver will allow you to use any beaconing mode
(AP | IBSS | Mesh) mode on DFS channels yet.

Note that not all 5 GHz channels require radar detection though so you
could try using one of the non-DFS channels. Check 'iw list' for that.

ath9k STA should work with DFS but I didn't work on that myself so
will leave someone else to comment on that.

  Luis

[ath9k-devel] Radar Detection and DFS status

[Sujith]

Luis R. Rodriguez wrote:
> mac80211 or ath9k does not yet have radar detection support so
> therefore no mac80211 driver will allow you to use any beaconing mode
> (AP | IBSS | Mesh) mode on DFS channels yet.
> 
> Note that not all 5 GHz channels require radar detection though so you
> could try using one of the non-DFS channels. Check 'iw list' for that.
> 
> ath9k STA should work with DFS but I didn't work on that myself so
> will leave someone else to comment on that.

Yep, STA mode should work fine, since 802.11h CSA support was added to
mac80211 recently.

Sujith
-- 
http://sujith-m.blogspot.com

Re: [ath9k-devel] Radar Detection and DFS status

[Sujith]

Luis R. Rodriguez wrote:
> mac80211 or ath9k does not yet have radar detection support so
> therefore no mac80211 driver will allow you to use any beaconing mode
> (AP | IBSS | Mesh) mode on DFS channels yet.
> 
> Note that not all 5 GHz channels require radar detection though so you
> could try using one of the non-DFS channels. Check 'iw list' for that.
> 
> ath9k STA should work with DFS but I didn't work on that myself so
> will leave someone else to comment on that.

Yep, STA mode should work fine, since 802.11h CSA support was added to
mac80211 recently.

Sujith
-- 
http://sujith-m.blogspot.com

[ath9k-devel] Radar Detection and DFS status

[Alberto Pollastro]

On Wed, Feb 11, 2009 at 10:41 PM, Luis R. Rodriguez <mcgrof@gmail.com> wrote:
>
> mac80211 or ath9k does not yet have radar detection support so
> therefore no mac80211 driver will allow you to use any beaconing mode
> (AP | IBSS | Mesh) mode on DFS channels yet.
>
> Note that not all 5 GHz channels require radar detection though so you
> could try using one of the non-DFS channels. Check 'iw list' for that.

I've checked in regdb (2009.01.30) an it reports that I can use these
frequencies (in Italy):

country IT:
    (2402 - 2482 @ 40), (N/A, 20)
    (5170 - 5250 @ 40), (N/A, 20)
    (5250 - 5330 @ 40), (N/A, 20), DFS
    (5490 - 5710 @ 40), (N/A, 27), DFS

I'm not sure, but in Italy the range 5170 - 5250 can be used only
indoor. Are indoor/outdoor channels treated differently by mac80211
and/or ath9k?

Regarding 802.11h, is its development for beaconing modes scheduled?

Thanks,
Albert.

Re: [ath9k-devel] Radar Detection and DFS status

[Alberto Pollastro]

On Wed, Feb 11, 2009 at 10:41 PM, Luis R. Rodriguez <mcgrof@gmail.com> wrote:
>
> mac80211 or ath9k does not yet have radar detection support so
> therefore no mac80211 driver will allow you to use any beaconing mode
> (AP | IBSS | Mesh) mode on DFS channels yet.
>
> Note that not all 5 GHz channels require radar detection though so you
> could try using one of the non-DFS channels. Check 'iw list' for that.

I've checked in regdb (2009.01.30) an it reports that I can use these
frequencies (in Italy):

country IT:
    (2402 - 2482 @ 40), (N/A, 20)
    (5170 - 5250 @ 40), (N/A, 20)
    (5250 - 5330 @ 40), (N/A, 20), DFS
    (5490 - 5710 @ 40), (N/A, 27), DFS

I'm not sure, but in Italy the range 5170 - 5250 can be used only
indoor. Are indoor/outdoor channels treated differently by mac80211
and/or ath9k?

Regarding 802.11h, is its development for beaconing modes scheduled?

Thanks,
Albert.

[ath9k-devel] Radar Detection and DFS status

[Luis R. Rodriguez]

On Thu, Feb 12, 2009 at 4:56 AM, Alberto Pollastro
<a.pollastro@gmail.com> wrote:
> On Wed, Feb 11, 2009 at 10:41 PM, Luis R. Rodriguez <mcgrof@gmail.com> wrote:
>>
>> mac80211 or ath9k does not yet have radar detection support so
>> therefore no mac80211 driver will allow you to use any beaconing mode
>> (AP | IBSS | Mesh) mode on DFS channels yet.
>>
>> Note that not all 5 GHz channels require radar detection though so you
>> could try using one of the non-DFS channels. Check 'iw list' for that.
>
> I've checked in regdb (2009.01.30) an it reports that I can use these
> frequencies (in Italy):
>
> country IT:
>    (2402 - 2482 @ 40), (N/A, 20)
>    (5170 - 5250 @ 40), (N/A, 20)
>    (5250 - 5330 @ 40), (N/A, 20), DFS
>    (5490 - 5710 @ 40), (N/A, 27), DFS
>
> I'm not sure, but in Italy the range 5170 - 5250 can be used only
> indoor. Are indoor/outdoor channels treated differently by mac80211
> and/or ath9k?

Yes, we have indoor and outdoor channel flags. You can supply a patch
or provide a reference to the regulatory information you are reading
to determine this and we can patch it up.

> Regarding 802.11h, is its development for beaconing modes scheduled?

I believe this will be worked on but we have no exact schedule.

  Luis

Re: [ath9k-devel] Radar Detection and DFS status

[Luis R. Rodriguez]

On Thu, Feb 12, 2009 at 4:56 AM, Alberto Pollastro
<a.pollastro@gmail.com> wrote:
> On Wed, Feb 11, 2009 at 10:41 PM, Luis R. Rodriguez <mcgrof@gmail.com> wrote:
>>
>> mac80211 or ath9k does not yet have radar detection support so
>> therefore no mac80211 driver will allow you to use any beaconing mode
>> (AP | IBSS | Mesh) mode on DFS channels yet.
>>
>> Note that not all 5 GHz channels require radar detection though so you
>> could try using one of the non-DFS channels. Check 'iw list' for that.
>
> I've checked in regdb (2009.01.30) an it reports that I can use these
> frequencies (in Italy):
>
> country IT:
>    (2402 - 2482 @ 40), (N/A, 20)
>    (5170 - 5250 @ 40), (N/A, 20)
>    (5250 - 5330 @ 40), (N/A, 20), DFS
>    (5490 - 5710 @ 40), (N/A, 27), DFS
>
> I'm not sure, but in Italy the range 5170 - 5250 can be used only
> indoor. Are indoor/outdoor channels treated differently by mac80211
> and/or ath9k?

Yes, we have indoor and outdoor channel flags. You can supply a patch
or provide a reference to the regulatory information you are reading
to determine this and we can patch it up.

> Regarding 802.11h, is its development for beaconing modes scheduled?

I believe this will be worked on but we have no exact schedule.

  Luis

[ath9k-devel] Radar Detection and DFS status

[Alberto Pollastro]

On Thu, Feb 12, 2009 at 4:53 PM, Luis R. Rodriguez <mcgrof@gmail.com> wrote:
> Yes, we have indoor and outdoor channel flags. You can supply a patch
> or provide a reference to the regulatory information you are reading
> to determine this and we can patch it up.

I've read the European Directive 2007/90/EC:

http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2007:041:0010:01:EN:HTML

I think that the EC directive has been acknowledged by the Italian
legislation as reported in the following table at page 28 (it's in
Italian, sorry):

http://www.comunicazioni.it/binary/min_comunicazioni/piano_nazionale_ripartizione_frequenze/03%20tabella_B.pdf

I hope I'm not wrong.

Thanks,
Albert.

Re: [ath9k-devel] Radar Detection and DFS status

[Alberto Pollastro]

On Thu, Feb 12, 2009 at 4:53 PM, Luis R. Rodriguez <mcgrof@gmail.com> wrote:
> Yes, we have indoor and outdoor channel flags. You can supply a patch
> or provide a reference to the regulatory information you are reading
> to determine this and we can patch it up.

I've read the European Directive 2007/90/EC:

http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2007:041:0010:01:EN:HTML

I think that the EC directive has been acknowledged by the Italian
legislation as reported in the following table at page 28 (it's in
Italian, sorry):

http://www.comunicazioni.it/binary/min_comunicazioni/piano_nazionale_ripartizione_frequenze/03%20tabella_B.pdf

I hope I'm not wrong.

Thanks,
Albert.

[ath9k-devel] Radar Detection and DFS status

[Luis R. Rodriguez]

On Thu, Feb 12, 2009 at 12:39:51PM -0800, Alberto Pollastro wrote:
> On Thu, Feb 12, 2009 at 4:53 PM, Luis R. Rodriguez <mcgrof@gmail.com> wrote:
> > Yes, we have indoor and outdoor channel flags. You can supply a patch
> > or provide a reference to the regulatory information you are reading
> > to determine this and we can patch it up.
> 
> I've read the European Directive 2007/90/EC:
> 
> http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2007:041:0010:01:EN:HTML
> 
> I think that the EC directive has been acknowledged by the Italian
> legislation as reported in the following table at page 28 (it's in
> Italian, sorry):
> 
> http://www.comunicazioni.it/binary/min_comunicazioni/piano_nazionale_ripartizione_frequenze/03%20tabella_B.pdf
> 
> I hope I'm not wrong.

Thanks the details, Michael, what do you think?

  Luis

Re: [ath9k-devel] Radar Detection and DFS status

[Luis R. Rodriguez]

On Thu, Feb 12, 2009 at 12:39:51PM -0800, Alberto Pollastro wrote:
> On Thu, Feb 12, 2009 at 4:53 PM, Luis R. Rodriguez <mcgrof@gmail.com> wrote:
> > Yes, we have indoor and outdoor channel flags. You can supply a patch
> > or provide a reference to the regulatory information you are reading
> > to determine this and we can patch it up.
> 
> I've read the European Directive 2007/90/EC:
> 
> http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2007:041:0010:01:EN:HTML
> 
> I think that the EC directive has been acknowledged by the Italian
> legislation as reported in the following table at page 28 (it's in
> Italian, sorry):
> 
> http://www.comunicazioni.it/binary/min_comunicazioni/piano_nazionale_ripartizione_frequenze/03%20tabella_B.pdf
> 
> I hope I'm not wrong.

Thanks the details, Michael, what do you think?

  Luis

[ath9k-devel] Radar Detection and DFS status

[Robert Meschke]

Hi,

I want to use GHz channels for outdoor WLAN communications in Germany. In this regdomain all outdoor 5GHz channels are DFS channels. I need 11n connection speeds. What's the status of DFS and Radar Detection in ath9k and mac80211 at this time? 
I am using OpenWrt and the only known issue is: "Currently 5 GHz channels do not work with mac80211 based drivers due to DFS regulatory issues."

How complex would it be to implement DFS for the AP mode myself? Advices would be extremely helpful. Thanks in advance

Regards
RM

[ath9k-devel] Radar Detection and DFS status

[Luis R. Rodriguez]

On Wed, Apr 28, 2010 at 2:27 AM, Robert Meschke <r_meschke@yahoo.de> wrote:
> Hi,
>
> I want to use GHz channels for outdoor WLAN communications in Germany. In this regdomain all outdoor 5GHz channels are DFS channels. I need 11n connection speeds. What's the status of DFS and Radar Detection in ath9k and mac80211 at this time?
> I am using OpenWrt and the only known issue is: "Currently 5 GHz channels do not work with mac80211 based drivers due to DFS regulatory issues."
>
> How complex would it be to implement DFS for the AP mode myself? Advices would be extremely helpful. Thanks in advance

To be compliant with DFS it requires quite a lot of expensive
equipment and time. Its something Atheros has considered implementing
but nothing firm on a schedule yet.

  Luis

[ath9k-devel] Radar Detection and DFS status

[Robert Meschke]

Hi,

thank you for your immediate response, Luis. It's a pity that DFS is not supposed to work in the near future. A can provide more specific information. I am working on a project, where I really need the 5 Ghz band and have to respect national laws.
I am using Ubiquiti Networks SR71-A MIMO mini pci radios, based on the Atheros AR 9160 bb/mac chip and AR5133 RF chip. I am really willing to implement DFS if it is somehow possible for me. 
Former in this thread it was mentioned that Radar Pulse Detection is done by hardware itself and is supported by madwifi. I've checked the madwifi-hal and the one of Sam Leffler for Radar Detection stuff. The AR9160 is declared as compatible with AR5416 in the ah_devid.h:

/* AR5416 compatible devid's  */
#define AR5416_DEVID_PCI    0x0023          /* AR5416 PCI (MB/CB) Owl */
#define AR5416_DEVID_PCIE    0x0024          /* AR5416 PCI-E (XB) Owl */
#define AR9160_DEVID_PCI    0x0027          /* AR9160 PCI Sowl */
#define AR9280_DEVID_PCI    0x0029          /* AR9280 PCI Merlin */
#define AR9280_DEVID_PCIE    0x002a          /* AR9280 PCI-E Merlin */
#define AR9285_DEVID_PCIE    0x002b          /* AR9285 PCI-E Kite */

Register adresses for Radar Detection are defined for AR5211+ in if_ath_radar.h. In the if_ath_radar.c this can be found:

if (ar_device(sc) >= 5211) {

...

}

It implies to me that Radar Detection performed by the madwifi Driver could possibly work for AR5416 (and therefore for AR9160, too).

It has to be mentioned that there are register adress definitions for Radar Detection in the hal of Sam Leffler but only for AR5211 and AR5212 and I've read in forum that the AR5416 does not have Radar Detection caps. 

Are the hardware interfaces for Radar Detection of AR9160 and AR5211/12 the same and is there any chance for madwifi code to work for ath9k too (after necessary modifications)?

Have anybody else information on this topic? I have access to signal generators an spectrum analysers, so I could verify compliance with DFS but I need the exact hardware specifications.
Thanks in advance.

my warm regards
Robert      

[ath9k-devel] Radar Detection and DFS status

[Benoit PAPILLAULT]

Robert Meschke a ?crit :
> Hi,
>
> thank you for your immediate response, Luis. It's a pity that DFS is not supposed to work in the near future. A can provide more specific information. I am working on a project, where I really need the 5 Ghz band and have to respect national laws.
> I am using Ubiquiti Networks SR71-A MIMO mini pci radios, based on the Atheros AR 9160 bb/mac chip and AR5133 RF chip. I am really willing to implement DFS if it is somehow possible for me. 
> Former in this thread it was mentioned that Radar Pulse Detection is done by hardware itself and is supported by madwifi. I've checked the madwifi-hal and the one of Sam Leffler for Radar Detection stuff. The AR9160 is declared as compatible with AR5416 in the ah_devid.h:
>
> /* AR5416 compatible devid's  */
> #define AR5416_DEVID_PCI    0x0023          /* AR5416 PCI (MB/CB) Owl */
> #define AR5416_DEVID_PCIE    0x0024          /* AR5416 PCI-E (XB) Owl */
> #define AR9160_DEVID_PCI    0x0027          /* AR9160 PCI Sowl */
> #define AR9280_DEVID_PCI    0x0029          /* AR9280 PCI Merlin */
> #define AR9280_DEVID_PCIE    0x002a          /* AR9280 PCI-E Merlin */
> #define AR9285_DEVID_PCIE    0x002b          /* AR9285 PCI-E Kite */
>
> Register adresses for Radar Detection are defined for AR5211+ in if_ath_radar.h. In the if_ath_radar.c this can be found:
>
> if (ar_device(sc) >= 5211) {
>
> ...
>
> }
>
> It implies to me that Radar Detection performed by the madwifi Driver could possibly work for AR5416 (and therefore for AR9160, too).
>
> It has to be mentioned that there are register adress definitions for Radar Detection in the hal of Sam Leffler but only for AR5211 and AR5212 and I've read in forum that the AR5416 does not have Radar Detection caps. 
>
> Are the hardware interfaces for Radar Detection of AR9160 and AR5211/12 the same and is there any chance for madwifi code to work for ath9k too (after necessary modifications)?
>
> Have anybody else information on this topic? I have access to signal generators an spectrum analysers, so I could verify compliance with DFS but I need the exact hardware specifications.
> Thanks in advance.
>   
Hi Robert,

If you have access to signal generators, I would suggest a very simple 
and easy start : try to add the code to detect pulse like it was done in 
madwifi-dfs (ported to madwifi/trunk BTW). Then, just send few pulses 
and you'll see if you AR9160 based card will detect it. This is how I 
did when writing madwifi-dfs... a long time ago :-).

Maybe 802.11n hardware has some stuff specific to radar detection since 
it probably needs to distinguish between primary & secondary channel. Is 
there someone (Luis?) that can confirm?

Regards,
Benoit

[ath9k-devel] Radar Detection and DFS status

[Robert Meschke]

Am 29.04.2010 22:15, schrieb Benoit PAPILLAULT:
> Hi Robert,
>
> If you have access to signal generators, I would suggest a very simple 
> and easy start : try to add the code to detect pulse like it was done 
> in madwifi-dfs (ported to madwifi/trunk BTW). Then, just send few 
> pulses and you'll see if you AR9160 based card will detect it. This is 
> how I did when writing madwifi-dfs... a long time ago :-).
>
> Maybe 802.11n hardware has some stuff specific to radar detection 
> since it probably needs to distinguish between primary & secondary 
> channel. Is there someone (Luis?) that can confirm?
>
> Regards,
> Benoit
>
>
Thank you very much Benoit! I'll do my best and give it a try. I'll 
report if I have success :-)

I would have a better feeling with that, if I knew more about the AR9160 
(Register adresses etc.). Does anybody else have a little more information?
Thanks!

Regards,
Robert

[ath9k-devel] Radar Detection and DFS status

[Alexander Egorenkov]

Am 01.05.2010 11:50, schrieb Robert Meschke:
> Am 29.04.2010 22:15, schrieb Benoit PAPILLAULT:
>> Hi Robert,
>>
>> If you have access to signal generators, I would suggest a very simple
>> and easy start : try to add the code to detect pulse like it was done
>> in madwifi-dfs (ported to madwifi/trunk BTW). Then, just send few
>> pulses and you'll see if you AR9160 based card will detect it. This is
>> how I did when writing madwifi-dfs... a long time ago :-).
>>
>> Maybe 802.11n hardware has some stuff specific to radar detection
>> since it probably needs to distinguish between primary&  secondary
>> channel. Is there someone (Luis?) that can confirm?
>>
>> Regards,
>> Benoit
>>
>>
> Thank you very much Benoit! I'll do my best and give it a try. I'll
> report if I have success :-)
>
> I would have a better feeling with that, if I knew more about the AR9160
> (Register adresses etc.). Does anybody else have a little more information?
> Thanks!
>
> Regards,
> Robert

Hi, i'm currently studying ath9k Linux driver and FreeBSD ath driver
and wanted also to know how DFS on Atheros works. And i found something
interesting in ath_hal on FreeBSD 8. I think it might interest you.

First you should look at file ar5212_recv.c.
There you will find the function ar5212SetRxFilter which activates
notifications about radar phy errors. Atheros notifies the driver about 
radar signal through Rx queue (Rx descriptors).

PHY error mask register is AR_PHY_ERR = 0x810c.
And to activate radar notification, you have to set bit AR_PHY_ERR_RADAR 
= 0x00000020 in this register.

When radar signal is detected by PHY then the PHY error flag (AR_PHYErr) 
is set in the Rx descriptor upon completion. Look at the function 
ar5212ProcRxDesc in the file ar5212_recv.c. This flag says that
a PHY error occurred. To determine which one happened you have to look 
at PHY eror code in the Rx descriptor.

I hope it will help you further :-)

Alex

[ath9k-devel] Radar Detection and DFS status

[Alexander Egorenkov]

Am 29.04.2010 22:15, schrieb Benoit PAPILLAULT:
> Robert Meschke a ?crit :
>> Hi,
>>
>> thank you for your immediate response, Luis. It's a pity that DFS is not supposed to work in the near future. A can provide more specific information. I am working on a project, where I really need the 5 Ghz band and have to respect national laws.
>> I am using Ubiquiti Networks SR71-A MIMO mini pci radios, based on the Atheros AR 9160 bb/mac chip and AR5133 RF chip. I am really willing to implement DFS if it is somehow possible for me.
>> Former in this thread it was mentioned that Radar Pulse Detection is done by hardware itself and is supported by madwifi. I've checked the madwifi-hal and the one of Sam Leffler for Radar Detection stuff. The AR9160 is declared as compatible with AR5416 in the ah_devid.h:
>>
>> /* AR5416 compatible devid's  */
>> #define AR5416_DEVID_PCI    0x0023          /* AR5416 PCI (MB/CB) Owl */
>> #define AR5416_DEVID_PCIE    0x0024          /* AR5416 PCI-E (XB) Owl */
>> #define AR9160_DEVID_PCI    0x0027          /* AR9160 PCI Sowl */
>> #define AR9280_DEVID_PCI    0x0029          /* AR9280 PCI Merlin */
>> #define AR9280_DEVID_PCIE    0x002a          /* AR9280 PCI-E Merlin */
>> #define AR9285_DEVID_PCIE    0x002b          /* AR9285 PCI-E Kite */
>>
>> Register adresses for Radar Detection are defined for AR5211+ in if_ath_radar.h. In the if_ath_radar.c this can be found:
>>
>> if (ar_device(sc)>= 5211) {
>>
>> ...
>>
>> }
>>
>> It implies to me that Radar Detection performed by the madwifi Driver could possibly work for AR5416 (and therefore for AR9160, too).
>>
>> It has to be mentioned that there are register adress definitions for Radar Detection in the hal of Sam Leffler but only for AR5211 and AR5212 and I've read in forum that the AR5416 does not have Radar Detection caps.
>>
>> Are the hardware interfaces for Radar Detection of AR9160 and AR5211/12 the same and is there any chance for madwifi code to work for ath9k too (after necessary modifications)?
>>
>> Have anybody else information on this topic? I have access to signal generators an spectrum analysers, so I could verify compliance with DFS but I need the exact hardware specifications.
>> Thanks in advance.
>>
> Hi Robert,
>
> If you have access to signal generators, I would suggest a very simple
> and easy start : try to add the code to detect pulse like it was done in
> madwifi-dfs (ported to madwifi/trunk BTW). Then, just send few pulses
> and you'll see if you AR9160 based card will detect it. This is how I
> did when writing madwifi-dfs... a long time ago :-).
>
> Maybe 802.11n hardware has some stuff specific to radar detection since
> it probably needs to distinguish between primary&  secondary channel. Is
> there someone (Luis?) that can confirm?
>
> Regards,
> Benoit

And AR9160 definetly supports DFS :-) Because it's a chipset for AP and 
routers for 2.4 and 5 GHZ band :-)
See http://www.atheros.com/news/AR9001.htm

[ath9k-devel] Radar Detection and DFS status

[Luis R. Rodriguez]

On Thu, May 6, 2010 at 1:36 PM, Alexander Egorenkov <egorenar@gmail.com> wrote:
> Am 29.04.2010 22:15, schrieb Benoit PAPILLAULT:
>> Robert Meschke a ?crit :
>>> Hi,
>>>
>>> thank you for your immediate response, Luis. It's a pity that DFS is not supposed to work in the near future. A can provide more specific information. I am working on a project, where I really need the 5 Ghz band and have to respect national laws.
>>> I am using Ubiquiti Networks SR71-A MIMO mini pci radios, based on the Atheros AR 9160 bb/mac chip and AR5133 RF chip. I am really willing to implement DFS if it is somehow possible for me.
>>> Former in this thread it was mentioned that Radar Pulse Detection is done by hardware itself and is supported by madwifi. I've checked the madwifi-hal and the one of Sam Leffler for Radar Detection stuff. The AR9160 is declared as compatible with AR5416 in the ah_devid.h:
>>>
>>> /* AR5416 compatible devid's ?*/
>>> #define AR5416_DEVID_PCI ? ?0x0023 ? ? ? ? ?/* AR5416 PCI (MB/CB) Owl */
>>> #define AR5416_DEVID_PCIE ? ?0x0024 ? ? ? ? ?/* AR5416 PCI-E (XB) Owl */
>>> #define AR9160_DEVID_PCI ? ?0x0027 ? ? ? ? ?/* AR9160 PCI Sowl */
>>> #define AR9280_DEVID_PCI ? ?0x0029 ? ? ? ? ?/* AR9280 PCI Merlin */
>>> #define AR9280_DEVID_PCIE ? ?0x002a ? ? ? ? ?/* AR9280 PCI-E Merlin */
>>> #define AR9285_DEVID_PCIE ? ?0x002b ? ? ? ? ?/* AR9285 PCI-E Kite */
>>>
>>> Register adresses for Radar Detection are defined for AR5211+ in if_ath_radar.h. In the if_ath_radar.c this can be found:
>>>
>>> if (ar_device(sc)>= 5211) {
>>>
>>> ...
>>>
>>> }
>>>
>>> It implies to me that Radar Detection performed by the madwifi Driver could possibly work for AR5416 (and therefore for AR9160, too).
>>>
>>> It has to be mentioned that there are register adress definitions for Radar Detection in the hal of Sam Leffler but only for AR5211 and AR5212 and I've read in forum that the AR5416 does not have Radar Detection caps.
>>>
>>> Are the hardware interfaces for Radar Detection of AR9160 and AR5211/12 the same and is there any chance for madwifi code to work for ath9k too (after necessary modifications)?
>>>
>>> Have anybody else information on this topic? I have access to signal generators an spectrum analysers, so I could verify compliance with DFS but I need the exact hardware specifications.
>>> Thanks in advance.
>>>
>> Hi Robert,
>>
>> If you have access to signal generators, I would suggest a very simple
>> and easy start : try to add the code to detect pulse like it was done in
>> madwifi-dfs (ported to madwifi/trunk BTW). Then, just send few pulses
>> and you'll see if you AR9160 based card will detect it. This is how I
>> did when writing madwifi-dfs... a long time ago :-).
>>
>> Maybe 802.11n hardware has some stuff specific to radar detection since
>> it probably needs to distinguish between primary& ?secondary channel. Is
>> there someone (Luis?) that can confirm?
>>
>> Regards,
>> Benoit
>
> And AR9160 definetly supports DFS :-) Because it's a chipset for AP and
> routers for 2.4 and 5 GHZ band :-)
> See http://www.atheros.com/news/AR9001.htm

DFS requires some software implemented which is not upstream, we are
reviewing this possibility now.

  Luis