On Tue, Nov 9, 2010 at 11:29 PM, Min-Wook Jeong <minw...@stanford.edu> wrote:
> Hi!
>Hi
> We would like to post a new question about the power and rate control.
>
> We have tried a power control with Netgear WNA1100 (ath9k_htc) adapter.
> Apparently, this adapter seems to be supporting power control as we can
> issue the command like
>
> sudo iw dev wlan1 set txpower fixed 1800
>
> and verify that the txpower is changed to 18dBm via 'iwconfig' output.
>
> However, actual signal strength measurement shows that the adapter uses the
> same power. Therefore, we inserted the code
>
> REG_WRITE(ah, AR_PHY_POWER_TX_RATE_MAX, MAX_RATE_POWER |
> AR_PHY_POWER_TX_RATE_MAX_TPC_ENABLE)
>
> you suggested in the driver and testing.
>
> We are curious about
>
> 1. Are 'ath9k' and 'ath9k_htc' different in terms of transmit power control
> (TPC)?
> 'ath9k' obviously supports TPC but if 'ath9k_htc' does not, we will try
> our experiment with another WLAN adapter with 'ath9k' driver.
I think yes ath9k_htc does supports TPC
>
> 2. It is about bitrate control. Currently, our device WNA1100 does not allow
> us to change the bitrate by issuing the command like
>
> sudo iw dev wlan1 set bitrates legacy-2.4 36
It worked for me.I had set the AP in legacy G mode and before
connecting to the AP I used this command.
I dont think this command will work after the connection is established.
Please do check whether the same thing is working if you connect to an
AP which is in mixed/'n' mode(NA mode,NG mode)
> Is it common with all adapters with 'ath9k' and 'ath9k_htc' or is is a
> problem with this particular adapter?
Please provide the lspci output.what card(s) are you using?
For ath9k_htc I think this may not be supported
Are you getting it like this?
command failed: Operation not supported (-95)
The Rate Control is handled in firmware,so this might be the reason
>
> 3. If we can do the bitrate control by setting up the proper register, could
> you tell us how to do that?
Dont know, I think it should be there some where .. I will look into
it, but you can work with the iw command know ? It will be supported
in most cards.
>
> Thank you,
> Min-Wook
>
> ________________________________
> From: "Min-Wook Jeong" <minw...@stanford.edu>
> To: "Lorenzo Bianconi" <lorenzo.biancon...@gmail.com>
> Cc: ath9k-devel@lists.ath9k.org, "Abdul Kader Kabbani"
> <akabb...@stanford.edu>, "Nick Bambos" <bam...@stanford.edu>,
> jmoun...@stanford.edu
> Sent: Wednesday, October 27, 2010 3:19:39 PM
> Subject: Re: [ath9k-devel] [Help] Performing per packet Power and Rate
> control
>
> Hi, Lorenzo!
>
> Thank you for your reply.
>
> Now as we try to implement our algorithm to the real wireless devices, we
> would like to purchase some Atheros WLAN adapters, whose specification
> requirements are as follows.
>
> - Adapters for laptop or netbooks with Linux.
> - Runs with Linux ath9k (or ath5k) driver.
> - Support of per-packet TPC, which users can manipulate via driver or Linux
> code. can . We are afraid that some adapters might support TPC physically
> but blocks users from playing with it.
> - Form factor: USB will be best. If not, CARDBUS/PCMCIA is our second
> choice.
>
> If you have a good adapter that fulfills the requirements, could you please
> let us know?
>
> Thank you,
> Min-Wook
>
> ________________________________
> From: "Lorenzo Bianconi" <lorenzo.biancon...@gmail.com>
> To: minw...@stanford.edu
> Cc: ath9k-devel@lists.ath9k.org
> Sent: Wednesday, October 27, 2010 10:54:56 AM
> Subject: Re: [ath9k-devel] [Help] Performing per packet Power and Rate
> control
>
>> Hi!
>>
>
> Hi,
>
>> We are trying to test a new link layer adaptation algorithm on a real
>> ath9k
>> WLAN cards.
>> For this, we want to change the transmission power and datarate for each
>> 802.11 frame.
>>
>> Can you tell me which part of the linux kernel we have to change to
>> implement this?
>>
>
> To change the TX power on frame basis, you have to enable TPC in the HW:
> REG_WRITE(ah, AR_PHY_POWER_TX_RATE_MAX, MAX_RATE_POWER |
> AR_PHY_POWER_TX_RATE_MAX_TPC_ENABLE)
> Please remember to enable this feature after each reset.
>
>> Thank you,
>> Min-Wook
>>
>> _______________________________________________
>> ath9k-devel mailing list
>> ath9k-devel@lists.ath9k.org
>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel
>>
>>
>
> Regards
>
> Lorenzo
>
> _______________________________________________
> ath9k-devel mailing list
> ath9k-devel@lists.ath9k.org
> https://lists.ath9k.org/mailman/listinfo/ath9k-devel
>
>
_______________________________________________
ath9k-devel mailing list
ath9k-devel@lists.ath9k.org
https://lists.ath9k.org/mailman/listinfo/ath9k-devel
