Return-path: Received: from mail-px0-f174.google.com ([209.85.212.174]:41986 "EHLO mail-px0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754483Ab1BGSc5 convert rfc822-to-8bit (ORCPT ); Mon, 7 Feb 2011 13:32:57 -0500 Received: by pxi15 with SMTP id 15so955675pxi.19 for ; Mon, 07 Feb 2011 10:32:57 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <4D5033DE.4070701@candelatech.com> References: <4D4EF004.3040109@candelatech.com> <4D4EF99D.5020601@openwrt.org> <4D4EFC76.6090000@candelatech.com> <4D4EFD87.4010005@openwrt.org> <4D4EFF68.9060101@candelatech.com> <4D4F0D83.4040401@candelatech.com> <4D4F0DFF.9010703@openwrt.org> <4D5033DE.4070701@candelatech.com> From: Daniel Halperin Date: Mon, 7 Feb 2011 10:32:37 -0800 Message-ID: Subject: Re: Scanning and channel types. To: Ben Greear Cc: Felix Fietkau , "linux-wireless@vger.kernel.org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: Start on 2.4 GHz AP with HT Only (not just HT40) set. That is, AP that doesn't allow 1 Mbps packets to be sent. Scan, make sure 1 mbps packets are sent. Start on 5 GHZ AP with HT Only set. Scan. What rate are probes sent at for 2.4 GHz? Dan On Mon, Feb 7, 2011 at 10:03 AM, Ben Greear wrote: > On 02/06/2011 09:42 PM, Daniel Halperin wrote: >> >> Right. I think there is a function something like "send_rate_low" that >> sends the lowest entry in the mac80211 enabled rates table for control >> and mgmt packets. ?If the NIC is associated to an HT Only AP then that >> lowest entry should be HT20 MCS 1, I'd think. >> >> Also, does circumventing "set channel type" code work properly across >> bands? ?If you start on 5 GHz will it send 6 Mbps probes or 1 Mbps >> probes? > > I did some tests with a sniffer set up: > > I have 8 STA vifs. > > 1) ?AP is setup to run on channel 11, HT40- > ? ?Let all associate on channel 11, radio goes to HT40- mode. > ? ?Run Scan on operating channel: > ? ?Probe request is reported as 1Mbps data rate on ch 11. > > 2) ?Scan on all channels: > ? ?Probe requests on 2.4Ghz channels are 1Mbps data rate. > ? ?Probe requests on 5Ghz channels (channel 40 in this case) > ? ?are reported as 6Mbps data rate. > > 3) ?Kill AP, no VIFS are associated (radio goes to NO_HT) > ? ?Run scan on all channels. > ? ?Probe request on channel 40 is 6Mbps data rate. > > > Please note that with my patches, the channel-type is still set to NO_HT > if we are scanning off the operating channel. ?Since test 1 appears to > function properly, I think that verifies that we can safely send NO_HT > requests while leaving the radio at HT40-. > > Please let me know if this answers your concerns. ?If you can think of > other combinations I should try, please let me know that as well. > > Thanks, > Ben > > -- > Ben Greear > Candela Technologies Inc ?http://www.candelatech.com > >