Sorry. I meant throughput. Let's considering GI=800ns - 20MHz: Without setting the MCS value the throughput is around 18Mbps. tx bitrate 58.5 MBit/s MCS 6 rx bitrate 48.0 MBit/s Then I set the bitrate to ht-mcs-2.4 13, 14 and finally 15. Although the tx bitrate increases as expected the maximum throughput is around 33Mbps tx bitrate: 117.0 MBit/s MCS 14 rx bitrate: 54.0 MBit/s I also tried the same with 40Mhz and the throughput doesn't change. The maximum throughput is always ~33Mbps. Even when the tx bitrate is 300Mbps the maximum throughput is still ~33Mbps. I noticed that the rx birate is related to the hwsim_rates from mac80211_hwsim, however, increasing the value provided by hwsim_rates doesn't change the throughput. My topology consists of three nodes. 2 clients and one AP working with hostapd. The hostapd config file includes ieee80211n=1 and ht_capab='[HT40+]'. Sometimes I can see that tx bitrate is working at 40Mhz. However, it doesn't work at 40Mhz when there are data traffic. The RSSI of both clients is -60dBm, but I also tried with -50dBm and -40dBm. Tested with both 2.4 and 5Ghz. This is my per.c file (https://github.com/ramonfontes/wmediumd/blob/ieee80211n/wmediumd/per.c). I only check if the rate-flags == IEEE80211_TX_RC_MCS and I force some of the rateset added in my per.c. Given this brief explanation I was wondering if it could be related to the number of antennas. Thank you in advance. Ramon Em qua, 21 de nov de 2018 às 06:11, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> escreveu: > > On Tue, 2018-11-20 at 16:33 -0300, Ramon Fontes wrote: > > Would be possible to simulate (or even add support to) multiple > > antennas? I was trying to extend wmediumd to 802.11n according the > > rates provided by http://mcsindex.com/, but the maximum rate I get is > > ~33Mbps, even if I set the MCS index to 15. Given the result, I > > thought that it could be related to the number of antennas. Is my > > assumption correct? > > I'm not sure what you mean by "the maximum rate I get is ~33Mbps". > > Are you trying to actually _measure_ it? Then, on a decent platform, you > should probably get many *gigabits*. > > Or are you trying to look at the rate in "iw station dump" or in > radiotap? Then you should see higher rates since hwsim is configured to > pretend to have 4 spatial streams (IIRC) > > johannes >
