Hello,<div><br></div><div>The ht_capab parameter in hostapd.conf enables 40MHz operation ([HT40-][HT40+]). I understand hostapd enables channel bonding only if there will be no channel/bandwidth overlap with neighboring APs (802.11n: scan for overlapping BSSes before starting 20/40MHz channel). Is there some way where I can control 40MHz vs. 20MHz operation myself without it being censored by hostapd?</div>
<div><br></div><div>Basically, I just want to be able to control channel bandwidth and operating channel using "iw dev wlan1 set freq 5745 HT20/HT40-/HT40+" while hostapd is running, and without being censored by hostapd. Is there any way to accomplish this? Is it a sensible option to resort to older 0.6.x distributions where there was just added support for configuring secondary channel offset for HT40? I am currently running hostapd v0.8.x, and these co-existence checks that limit the use of 40MHz were added in 0.7.x. If it is not a sensible option, I can alternatively modify hw_features.c (particularly the "ieee80211n_check_40mhz" function) and hostapd.c for recent hostapd versions. However, I still want to be able to control bandwidth operation with "iw".</div>
<div><br></div><div>My PC card supports: HT20/HT40, RC HT40 SGI, DSSS/CCK HT40. My ht_capab = [HT40-][HT40+][DSSS_CCK-40]. The iw list output for my PC card is:</div><div>
<br></div><blockquote class="webkit-indent-blockquote" style="margin: 0 0 0 40px; border: none; padding: 0px;"><div><span class="Apple-style-span" style="border-collapse: collapse; font-family: arial, sans-serif; font-size: 13px; "><div>
Capabilities: 0x104e</div></span></div></blockquote><div><meta http-equiv="content-type" content="text/html; charset=utf-8"><span class="Apple-style-span" style="border-collapse: collapse; font-family: arial, sans-serif; font-size: 13px; "><div>
<span style="white-space: pre-wrap; "> </span>HT20/HT40</div><div><span style="white-space: pre-wrap; "> </span>SM Power Save disabled</div><div><span style="white-space: pre-wrap; "> </span>RX HT40 SGI</div><div><span style="white-space: pre-wrap; "> </span>No RX STBC</div>
<div><span style="white-space: pre-wrap; "> </span>Max AMSDU length: 3839 bytes</div><div><span style="white-space: pre-wrap; "> </span>DSSS/CCK HT40</div><div><span style="white-space: pre-wrap; "> </span>Maximum RX AMPDU length 65535 bytes (exponent: 0x003)</div>
<div><span style="white-space: pre-wrap; "> </span>Minimum RX AMPDU time spacing: 8 usec (0x06)</div><div><span style="white-space: pre-wrap; "> </span>HT TX/RX MCS rate indexes supported: 0-15</div><div><span style="white-space: pre-wrap; "> </span>Frequencies:</div>
<div><span style="white-space: pre-wrap; "> </span>* 5180 MHz [36] (17.0 dBm)</div><div><span style="white-space: pre-wrap; "> </span>* 5200 MHz [40] (17.0 dBm)</div><div><span style="white-space: pre-wrap; "> </span>* 5220 MHz [44] (17.0 dBm)</div>
<div><span style="white-space: pre-wrap; "> </span>* 5240 MHz [48] (17.0 dBm)</div><div><span style="white-space: pre-wrap; "> </span>* 5260 MHz [52] (20.0 dBm) (passive scanning, no IBSS, radar detection)</div><div><span style="white-space: pre-wrap; "> </span>* 5280 MHz [56] (20.0 dBm) (passive scanning, no IBSS, radar detection)</div>
<div><span style="white-space: pre-wrap; "> </span>* 5300 MHz [60] (20.0 dBm) (passive scanning, no IBSS, radar detection)</div><div><span style="white-space: pre-wrap; "> </span>* 5320 MHz [64] (20.0 dBm) (passive scanning, no IBSS, radar detection)</div>
<div><span style="white-space: pre-wrap; "> </span>* 5500 MHz [100] (20.0 dBm) (passive scanning, no IBSS, radar detection)</div><div><span style="white-space: pre-wrap; "> </span>* 5520 MHz [104] (20.0 dBm) (passive scanning, no IBSS, radar detection)</div>
<div><span style="white-space: pre-wrap; "> </span>* 5540 MHz [108] (20.0 dBm) (passive scanning, no IBSS, radar detection)</div><div><span style="white-space: pre-wrap; "> </span>* 5560 MHz [112] (20.0 dBm) (passive scanning, no IBSS, radar detection)</div>
<div><span style="white-space: pre-wrap; "> </span>* 5580 MHz [116] (20.0 dBm) (passive scanning, no IBSS, radar detection)</div><div><span style="white-space: pre-wrap; "> </span>* 5600 MHz [120] (disabled)</div><div>
<span style="white-space: pre-wrap; "> </span>* 5620 MHz [124] (disabled)</div><div><span style="white-space: pre-wrap; "> </span>* 5640 MHz [128] (disabled)</div><div><span style="white-space: pre-wrap; "> </span>* 5660 MHz [132] (20.0 dBm) (passive scanning, no IBSS, radar detection)</div>
<div><span style="white-space: pre-wrap; "> </span>* 5680 MHz [136] (20.0 dBm) (passive scanning, no IBSS, radar detection)</div><div><span style="white-space: pre-wrap; "> </span>* 5700 MHz [140] (20.0 dBm) (passive scanning, no IBSS, radar detection)</div>
<div><span style="white-space: pre-wrap; "> </span>* 5745 MHz [149] (30.0 dBm)</div><div><span style="white-space: pre-wrap; "> </span>* 5765 MHz [153] (30.0 dBm)</div><div><span style="white-space: pre-wrap; "> </span>* 5785 MHz [157] (30.0 dBm)</div>
<div><span style="white-space: pre-wrap; "> </span>* 5805 MHz [161] (30.0 dBm)</div><div><span style="white-space: pre-wrap; "> </span>* 5825 MHz [165] (30.0 dBm)</div><div><span style="white-space: pre-wrap; "> </span>Bitrates (non-HT):</div>
<div><span style="white-space: pre-wrap; "> </span>* 6.0 Mbps</div><div><span style="white-space: pre-wrap; "> </span>* 9.0 Mbps</div><div><span style="white-space: pre-wrap; "> </span>* 12.0 Mbps</div><div><span style="white-space: pre-wrap; "> </span>* 18.0 Mbps</div>
<div><span style="white-space: pre-wrap; "> </span>* 24.0 Mbps</div><div><span style="white-space: pre-wrap; "> </span>* 36.0 Mbps</div><div><span style="white-space: pre-wrap; "> </span>* 48.0 Mbps</div><div><span style="white-space: pre-wrap; "> </span>* 54.0 Mbps</div>
</span></div><div><br></div><div>Given my hardware capabilities, I should be able to channel bond every channel with its adjacent channel. Hostapd restricts channel bonding to particular channels. Is there a reason for that? And how can I remove that restriction?</div>
<div><br></div><div>Furthermore, according to the kernel logs, my EEPROM is set to US 0x3a (CRDA updates the regulatory domain for my card I guess). Is this the reason why the UNI-2 band is labeled as "<span class="Apple-style-span" style="border-collapse: collapse; font-family: arial, sans-serif; font-size: 13px; ">(passive scanning, no IBSS, radar detection)"? I want to ask if this is a limitation set by the ath9k driver, and not my actual hardware. I would like to be able to use those channels to do DFS, and was wondering if that was a software vs. hardware limitation.</span></div>
<div><span class="Apple-style-span" style="border-collapse: collapse; font-family: arial, sans-serif; font-size: 13px; "><br></span></div><div><span class="Apple-style-span" style="border-collapse: collapse; font-family: arial, sans-serif; font-size: 13px; ">I am sorry if I crammed too many questions in one email. Thank you for your patience :)</span></div>
<meta http-equiv="content-type" content="text/html; charset=utf-8"><div><br></div><div>Regards,</div><div>Lara</div>