From mboxrd@z Thu Jan 1 00:00:00 1970 From: Date: Sun, 19 Dec 2010 23:59:03 -0000 Subject: No subject 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 * 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 > >