From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Chadd Date: Thu, 17 Feb 2011 11:11:43 -0500 Subject: [ath9k-devel] Progress on Ath9k HT support on Adhoc mode In-Reply-To: References: Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ath9k-devel@lists.ath9k.org I suggest watching minstral "walk its walk" as it tries different rates and see what the pass/fail/retry/times are for each of the rates. Take a look for rc_stat in the /sys filesystem, somewhere under ieee80211 or something similar; I don't have a Linux box handy to check. Adrian On 17 February 2011 04:27, Baldomero Coll wrote: > Thank you for your illustrative answer adrian. > I've sent an email today to the mailing list showing my performance in HT > IBSS mode. > > What happens now is that my ad-hoc link don't support HT in both > directions. One of the stations seems to stay in legacy IBSS mode, although > sometimes it upgrades to HT mode. > > I suppose it is due to the link adaptation mechanism (Minstrel HT?), but I > would also investigate if the station that stay in legacy IBSS mode is the > one who creates the HT network, the one who joins the HT network, or if it > don't really depend on that. > > 2011/2/16 Adrian Chadd > > Hi, >> >> From my understanding: >> >> * If your RX chainmask has >1 radio enabled, you'll always be doing >> receive-side "diversity" (which is really "combining" (MRC) if I >> understand the technology correctly on multi-radio atheros 11n cards); >> * If your TX chainmask has >1 radio enabled and the TX descriptor has >> the relevant chainmask bits set, you should be transmitting on both >> antennas regardless of the rate. I honestly haven't verified it (I've >> only verified that behaviour for transmitting legacy rates out of the >> 11n chips); >> >> * For rates < MCS8 (and legacy rates) there's further TX-side trickery >> that can be going on which I'm not too up-to-date on. For example, >> some (all?) of the 11n chips allow you to optionally transmit MCS0-7 >> using STBC. But iirc, STBC is only enabled for 1-stream TX. >> >> In short, if you've got all the radios enabled for RX and ath9k is >> enabling both/all radio chains when TX'ing, I think the answer is >> "yes" for you. :) >> >> Adrian >> >> On 16 February 2011 22:47, Baldomero Coll wrote: >> > I'm not sure, but I've read somewhere that by default the two antennas >> are >> > used. >> > It is true that I'm not interested in selecting the number of antennas, >> what >> > I really want is that the MIMO capability is exploited if I'm using >> 802.11n >> > HT IBSS operation mode. >> > Can someone confirm that by default the two antennas (spatial diversity) >> are >> > being used when we create the HT IBSS network? >> > >> > 2011/2/16 Mohammed Shafi >> >> >> >> On Tue, Feb 15, 2011 at 2:35 PM, Baldomero Coll > > >> >> wrote: >> >> > Hello, >> >> > >> >> > Can you please tell me how do you select one o two antennas? >> >> >> >> I don't know why you should do that. I guess changing the tx/rx >> >> chainmask will do after it was read from eeprom. >> >> >> >> > >> >> > I'm using a similar setting than you: >> >> > Linux kernel: 2.6.32-28-generic-pae. >> >> > Driver: compat-wireless-2011-01-17 and iw-0.9.21 with the patch >> >> > suggested by >> >> > Alex. >> >> > Radio card: Ubiquiti SR71x >> >> > >> >> > Thanks in advance, >> >> > Baldomero >> >> >> >> >> >> Hi all, >> >> >> >> >> >> I would like to confirm my findings. My test platform configurations >> >> >> are >> >> >> follow. >> >> >> Board: pcengine alix3d2 >> >> >> Linux kernel: 2.6.35 from linux-wireless git >> >> >> Driver: compat-wireless-2011-01-17 and iw-0.9.21 with the patch >> >> >> suggested by Alex. >> >> >> Radio card: Ubiqiti SR71a on channel 36 with HT40+ >> >> >> Measurement tool and settings: Iperf, UDP, 100Mb offered load >> >> >> >> >> >> Recored throughput: 50-54Mbps (one antenna); 78-80Mbps (two or three >> >> >> antennas). >> >> > >> >> > >> >> > _______________________________________________ >> >> > ath9k-devel mailing list >> >> > ath9k-devel at lists.ath9k.org >> >> > https://lists.ath9k.org/mailman/listinfo/ath9k-devel >> >> > >> >> > >> > >> > >> > _______________________________________________ >> > ath9k-devel mailing list >> > ath9k-devel at lists.ath9k.org >> > https://lists.ath9k.org/mailman/listinfo/ath9k-devel >> > >> > >> > > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20110217/33fe13ab/attachment.htm