Is Atheros XR (extended range) mode supported?

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michiganbroadband
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PostPosted: Mon Jun 14, 2010 20:15    Post subject: Is Atheros XR (extended range) mode supported? Reply with quote
I'd like to try DD-WRT Professional on EOC-2610's
and be able to use extended range (xr) mode.

Is this available & supported on this device?
And is it supported in both AP or Client modes?

I keep hearing/reading that XR mode is only supported on certain hardware but have not seen any definition of what hardware/chipsets this means..
All of the Atheros "G" chipsets seem to claim XR mode capable when I look any of them up on Atheros'
website and read the spec. sheets.

I'll try to keep this thread to "Will it work on the 2610" or not.
-edit- Yeah right (haha) :-)

Meanwhile please also see my other thread at:

http://www.dd-wrt.com/phpBB2/viewtopic.php?t=73249

As I'd really like to know definitively what works what does not work and why.

THANKS!

Steve


Last edited by michiganbroadband on Fri Jun 18, 2010 14:09; edited 2 times in total
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GeeTek
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PostPosted: Wed Jun 16, 2010 5:23    Post subject: Re: Is Atheros XR (extended range) mode supported? Reply with quote
michiganbroadband wrote:
I'd like to try DD-WRT Professional on EOC-2610's
and be able to use extended range (xr) mode.

Is this available & supported on this device?

No, but DD-WRT has a good functional substitute that allows you to specify the distance of the link so as to provide a decent ACK timing value. This will accomplish the same thing for specific distanced links.

XR mode strips the ACK out of the protocol so that you can achive full bandwidth at any distance. Don't hold yer breath on seeing this in DD-WRT. I've been asking for this for years. ACK + WIFI = ASININE, but it looks slick in the GUI.
BrainSlayer
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PostPosted: Thu Jun 17, 2010 15:03    Post subject: Reply with quote
atheros removed XR from the chipsets, thats the reason
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michiganbroadband
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PostPosted: Thu Jun 17, 2010 16:28    Post subject: Reply with quote
BrainSlayer:

True All of the NEWER Atheros Chipsets 9XXX etc.
The stuff that now is pushing 802.11n has dropped
XR mode..
Out of frustration and persistence I am now in direct contact with Atheros on my questions about XR mode.
Nobody in the whole world either knows or wants to
answer what I have been asking about. :)

Can you please be more specific for me?
I have done extensive research (to the best of my ability) over the past 6 months.
Most ALL of the Atheros chipsets I have come across
(AR platforms) that were built from end 2003-2007?8
meaning any/all of the 802.11G chips (NOT 802.11N).
All support XR mode per the documentation on the
Atheros website.

This includes the chipset in the Senao/Engenius
EOC-2610

At least the hardware docs claim to support XR mode.
Whether or not this is true or if it's a driver limitation I do not know..

It's likely you know way more than I do on this.
Are you able to list specfically what chips/hardware
do indeed support XR mode and which do not?

I'm rather frustrated that people keep telling me that some hardware does not support xr mode yet they
are unable to tell me specifically which does and which does not and why.

Meanwhile the Atheros site docs claim these Atheros
chips DO support xr mode.

Really I want to get to the factual information on this and go about using XR mode.

Who in their right mind would not want to have access
to this longer range mode (if it really exists).
And be able to try some weak signal work below the threshold where 802.11b 1Mbps mode fails.

I understand ALL of the newest chips do not support XR.
But we are talking about the chips that do and all of this equipment that has Atheros chips that supposedly do actually support it.

Sorry I'm getting way off topic here and I have another thread on the matter at:

http://www.dd-wrt.com/phpBB2/viewtopic.php?t=73249


BS: thanks for responding really I am looking for more definitive info:what works and what does not +why.
And I have searched & looked heavily for this information.

I'm not going to stop until I find out exactly
what the deal is with Atheros XR.
Is it for real or bullshit. :-)


I have yet to see it actually work..
Even with windows drivers and commercially available
"extended range" products that supposedly have it.

I've tested in many environments confirmed noise free
as well as in noisy/busy environments.
Yes I have actually created a 'noise free' test environment by driving out to an unpopulated unpowered area and did free space testing on battery powered stuff using NETGEAR branded commercially available off-the-shelf "rangemax" equipment.
Took the equipment to it's range limits and watched it switch between 802.11b mode (1mbps) and XR mode 500K and 256K as indicated.. in no event did the 500K or 256K mode EVER actually work and pass traffic.
Also in ALL cases I could never get a re-association to an access point until wandering back into 802.11b 1Mbps range... so it was obvious that 256K XR mode beaconing and AP association are not working at all in that mode.. even with commercially available off-shelf equipment and windows drivers that are supposed to support it.
The companys that make ths stuff *NETGEAR* are absolutely useless on advanced features and do not support them even though the product claims to.
Calling their support.. they don't even know what XR mode is or have any way to support & test it.
And yes I'm VERY aware that you might have to adjust various settings on AP and client for XR mode to work. enabling/disabling SuperG/Turbo having the wireless in the right modulation mode or mix mode
Channel# etc.. Yes I've tried every possibility under the sun as well as other AP's and client cards
& firmware & drivers. in Windows (especially) and in Linux.

I'm near the point of going public and declaring Atheros XR mode as total fraud..
Bullshit..

I've not read a single account on the Internet of someone actually testing it and observing it to work.

& I have looked & looked & looked & asked & asked & asked!

:-)

Steve
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PostPosted: Thu Jun 17, 2010 16:51    Post subject: Reply with quote
BrainSlayer wrote:
atheros removed XR from the chipsets, thats the reason

Thanks for clarifying, I did not realize this and I apologize for my off-handed remark.

michiganbroadband wrote:
Who in their right mind would not want to have access
to this longer range mode (if it really exists).
And be able to try some weak signal work below the threshold where 802.11b 1Mbps mode fails.

You seem to not fully understand what XR mode was. It does not allow for communicating with weaker signals. It has to do with the timing mechanism in the WIFI protocol which facilitates packet re-send when a packet is lost. If the distance is greater than what the timing is set for then the re-send rate goes up and hoses the link. With DD-WRT you can manually adjust this timing parameter to make long distance links funtion properly. Again, this does not relate to signal strength or weak signals, and neither did "XR mode". The distance window of ACK timing is about one mile.
Sash
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PostPosted: Thu Jun 17, 2010 17:22    Post subject: Reply with quote
GeeTek wrote:
BrainSlayer wrote:
atheros removed XR from the chipsets (92xx, etc), thats the reason

Thanks for clarifying, I did not realize this and I apologize for my off-handed remark.


fyi
also "turbo mode" for non N speeds was removed! ...as i found out yesterday

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michiganbroadband
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PostPosted: Fri Jun 18, 2010 2:09    Post subject: Reply with quote
GeeTek,

Thanks for responding and trying to help out.
Please see and read the following links so that you can better understand Atheros XR mode
what it is and how it works.
I get no joy at all in pointing out that you are incorrect.
Your information is useful and appreciated but does not apply to Atheros XR.
I just want to get XR mode to work on Atheros hardware :-)

Atheros Official documentation on XR: http://www.atheros.com/pt/whitepapers/atheros_XR_whitepaper.pdf

3RD party article with data from Atheros:

http://www.theregister.co.uk/2003/09/15/atheros_triples_wifi_range/

I have done my homework on this and understand exactly how it should work.

Although ACK timing is important on long haul links especially those over 1KM
This has absolutely nothing to do with Atheros XR mode itself and what I am trying to
use from the Atheros chipsets.


Atheros XR mode is a proprietary use of OFDM (3Mbps,1Mbps,500Kbps and 256Kbps) to allow data reception at signal strengths down to -105dBm and at a lower speed resulting in greater range at the cost of speed. Whereas the same chipset in 802.11b mode at its lowest speed (1Mbps) gives a reciever sensitivity
of around -95dBm.

Understanding how it's supposed to work has been easy for me (read the docs), but getting it to actually work in real life has been the incredible frustration, and this is bordering on fraud/false
advertisement from both Atheros 2003-2007 and from what I have seen of commercial product manufacturers
that supposedly support extended rage mode.
My experience thus far is that the manufacturers go and say it's there (built in) because Atheros
claims it's there but they dont provide support for it or a means to test and verify it's there.
My verification tests all so far have shown failure of XR mode to work.
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PostPosted: Fri Jun 18, 2010 2:26    Post subject: Reply with quote
michiganbroadband wrote:
Atheros XR mode is a proprietary use of OFDM (3Mbps,1Mbps,500Kbps and 256Kbps) to allow data reception at signal strengths down to -105dBm and at a lower speed resulting in greater range at the cost of speed.

Aha ! I did not realize that your goal was to eak out a dial-up speed connection from a WIFI connection in very low noise conditions. This is not a typical objective these days with 800 mW radios available for $75.

Here are a couple of links you might find of interest. I've got 8 or 9 of the D-Link DWL-2100 radios in a box somewhere if you are interested in playing with XR mode. You must realize that this is a quest into antiquity, and it would really behoove you to embrace current technology. Like BrainSlayer siad, XR is no longer a part of modern chipsets. Whatever references in current hardware you may be finding is obviously marketing speak that is not valid.

http://www.dslreports.com/forum/remark,13723573

http://www.dd-wrt.com/phpBB2/viewtopic.php?t=12295&postdays=0&postorder=asc&start=15

Edit - Going from a 1 Mbps link rate ( available now ) to a 250 Kbps link rate will give a 6 dB advantage, but you are approaching NATURAL background noise levels, and a TCP throughput of about 100 Kbps. Is this something you really need to explore ?
michiganbroadband
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PostPosted: Fri Jun 18, 2010 5:18    Post subject: Reply with quote
It certainly is and has been something I need to explore.. especially if it's there and even remotely
possible to use it and call upon it when needed.
6dB is 6 dB
Actually if you go per the EOC-2610 spec it would be 8dB better (-97dBm for b/1Mbps and -105dBm for XR)
and where I intend to use it is just below 2412Mhz for legitimate legal licensed use in the amatuer radio band in the US Smile (It's pretty quiet there).
100Kbps throughput is perfectly fine for the intended use.

100Kbps is also better than 0 Kbps on the coverage edges to roaming outdoor clients that we will be playing around with.

Now beside all of that I just need to play as well..
To me it's fun. I'd like to see it actually work ofdm
at 256K like it is supposed to and documented it can do.
I've never seen it work yet :-)

Great links & info you provide especially concerning the ack time mods themself..
But still no actual reports of testing of 256K mode
from anyone. :-)

The one thread that addressed this ended with an unanswered question of:

<
It seems that "set rate 0.25" doesn't work on European versions of DWL-2100AP: "Invalid parameter: 0.25". What version of HW/FW do you use?
>

And of course those instructions seem to apply only to a specific commercial firmware for a DWL2100.

Not exactly something I can try out here myself at the moment Smile but very interesting.

What I do have at the moment that I can play with and have been testing with lately are:

Some Atheros based USB WN111 extended range adaptors
Several Atheros based WPN824v3 extended range Access points.
Some Atheros based A/B/G PCMCIA NICS
Some Atheros based AR5004 and AR5005 mini-pci XR capable NICS.

Some FON 2100 Atheros based APs (DD-WRT latest installed)

Some Senao EOC-2610s (DD-WRT, latest stock firmware or openwrt KAMIKAZE 8.09.1 installed)

A DLINK DI-614v2 extended range AP (Latest firmware installed).

And some other stuff I've not thought of Smile


Last edited by michiganbroadband on Fri Jun 18, 2010 14:20; edited 1 time in total
michiganbroadband
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PostPosted: Fri Jun 18, 2010 7:15    Post subject: Reply with quote
Quote:

I've got 8 or 9 of the D-Link DWL-2100 radios in a box somewhere if you are interested in playing with XR mode.


Certainly! (especially if they actually work haha)

Quote:

You must realize that this is a quest into antiquity,


I've certainly considered that but nah.. there have been so many nics & access point/gateways made between 2004-2007/8
that incorporate the Atheros chips that support XR that they will be readily available for a few more years (at least 5 yrs) used & surplus.
There are always other narrowband 2.4GHz data options to consider as well as DECT 1.9GHz datamodem
modules that can offer a similar low speed high sensitivity radio to play with.
On the more expensive side are 900MHz options and transverters to 2.4GHz CH6. which offer more range and less line of sight retriction and path loss.
As well as new items that may come out in the next 5
years that offer more range than current items as
those wonderful Atheros XR mode devices start to become somewhat extinct Smile
But with the abundance of items out there now new used & surplus and with how nice XR sounds (at least how Atheros puts it), I have deemed it more than worthwhile to pursue. There is also a rising demand in the US (although not very well known or heard about here in the DD-WRT or openwrt communities for amatuer radio (ham) use of the lower non FCC part 15 portion of the 2.4GHz spectrum using such things at Atheros' XR mode, Atheros 5MHz channel ofdm mode etc. in their exclusive use part of the band where they do not have to share with FCC part 15 unlicensed users on Wifi CH 1-6.

One of the benefits of XR mode is that like ofdm quarterchannel mode it uses less RF(radio) bandwidth than a standard 802.11b or g signal (1 or 2MHz vs. 5 or 20MHz).
XR mode goes even less than 5MHz *I think* which is attractive to hams that want to operate radios under channel 1 without getting interference (noise) from Part 15 users up on CH1-6 which works out way better or them if they are operating in a narrow bandwidth/low speed mode versus a full 20MHz channel mode.


Last edited by michiganbroadband on Fri Jun 18, 2010 14:30; edited 1 time in total
Sash
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PostPosted: Fri Jun 18, 2010 10:58    Post subject: Reply with quote
i think XR uses the 20mhz channels to be compatible to standard equipment. so wouldnt it be better to use 5mhz to increase range (this automaticly reduces original 1mbps signals to 256kbps)? it would also have better penetration in noisy areas.

btw i would be interested in 5mhz testing results *g*

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PostPosted: Fri Jun 18, 2010 13:05    Post subject: Reply with quote
I *think* that XR actually uses less bandwidth itself
but maintains RTS/CTS *type* of communication on a standard 802.11b modulation at the same time so that
other stations that cannot communicate XR know that
the channel is in use and share it properly..
Likewise the stations that happen to be out of 802.11b or 802.11g range and are only communicating to the AP in XR mode get some sort of rts/cts
flow control from the AP (in their native XR mode)when the AP is holding off and waiting for use of channel while it's hearing
802.11b or G traffic from it's vantage point.
The clients would do the same thing if they see/hear 802.11bg stations in range of themselves that the AP does not hear or see.] mainly with an RTS/CTS type of mechanism, telling the AP to hold off until I see the channel as available again.
That is purly my speculation from what I have read
in how the two technologies can cooexist happily.
It would be nice if it were actually documented in how it really works.

But yes Sash.. it's certainly reasonable to assume that XR mode could be using an entire 20 MHz channel
and sending the same amount of raw data through the air, but in a very redundant fashion where the over the air bits (chips) PN sequence still results in
a 20MHz channel bandwidth but due to the low actual
decoded data rate (256kbps) results in MUCH higher processing gain figure thus the greater ability to
pull out a weaker signal down to -105dBm under optimal conditions. :-)



5MHz mode is much easier to at least get running
than is XR. :-)

Per my direct conversation with Atheros:
5MHz mode is quarter standard OFDM (1/4 of 6Mbps)
Raw data speed would be 2Mbps
so per my converstation with my contact at Atheros..
There would be a theroetical 6dB gain over the
published ofdm 6Mbps reciever sensitivity figure
of -92dBm = -97dBm optimally.
Which is the same published figure for 802.11b 1Mbps
on a Senao EOC-2610.
So certainly a cool mode and twice the datarate
at the same S/N :-)

But not the -105dBm that you can supposedly pull
with XR. (XR being 8dB more sensitive).
michiganbroadband
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PostPosted: Fri Jun 18, 2010 13:10    Post subject: Reply with quote
Good thinking Sash, but 5MHz mode uses ofdm only.
Standard ofdm only goes down to 6Mbps.
And in 5MHz mode it goes down to 2Mbps at it's
lowest available connection rate.
In 20 MHz mode you only ever get 1Mbps 2Mbps and 5.5Mbps if the radio switches out of ofdm mode(802.11g) and into 802.11b mode Smile FYI.
And quarterchannel mode (5MHz) does not work with
802.11b -->1,2,5.5 and 11Mbps.
michiganbroadband
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PostPosted: Tue Jul 13, 2010 1:07    Post subject: Reply with quote
XR mode seems to be bullshitware.
it never really existed or was never really implemented..

There is no public account of it ever working or being tested compared reviewed in either Linux or Windows.
Nobody I've talked with knows anything about or has ever seen this work..

If they have, they are not willing to share information.

Atheros + any entitiy that sells XR mode enabled devices has never been publicly challenged or reviewed or otherwise documented on the XR feature
other than repeat of the sales information and what the feature promised to offer.

This is my opinion and is based on 6 months of solid digging & research.

I am and have been in direct contact with Atheros on the subject and I'm told it's no longer sold or supported.
Nobody including Atheros is able to share with me any example of a working product pair /access point + card that have ever used
XR mode everyone sems to have just avoided it.
And it has been swept under the rug.
Probably because it never worked as claimed in the first place.
Stupid, dumb & irritating to me..
Frustrating..

So if Atheros is not going to support it I guess nobody else is either.

We'll just continue to be happy sheep with -95dBm
RX sensitivity @1Mbps and not get that extra -105dBm
sensitivity that Atheros promised & claimed on all
their chipsets back in 2004 & 2005.
*smile* *blink*

I'll keep trying.

It would have been interesting to get that working for long DX links and longer reach to client cards
outdoors as this is the enviroment I play in often.

I have other narrow band proprietary options that I can seek out for extended range on 2.4GHz
And it seems that is where I will have to go for that.
XR would have been nice if it had been for real.
and supported and actually gave a range boost.
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PostPosted: Wed Jul 14, 2010 2:59    Post subject: Reply with quote
michiganbroadband wrote:
...There is no public account of it ever working or being tested ...

Not that I'm particularly inclined to feed yer silly frenzy, but you seem to have disregarded some of the links I posted.

I relied on XR mode for about 2 years before Brainslayer finally started including ACK timing in his broadcom builds. XR mode was real and it worked great.
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