Return-path: Received: from mail-ob0-f173.google.com ([209.85.214.173]:33075 "EHLO mail-ob0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751757AbaJYS50 (ORCPT ); Sat, 25 Oct 2014 14:57:26 -0400 Received: by mail-ob0-f173.google.com with SMTP id wp4so1736619obc.4 for ; Sat, 25 Oct 2014 11:57:26 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <544AA2F9.6050806@gmail.com> References: <544AA2F9.6050806@gmail.com> Date: Sat, 25 Oct 2014 19:10:02 +0300 Message-ID: (sfid-20141025_205729_946287_6D0CB4C3) Subject: Re: Channel Estimation Question From: Emmanuel Grumbach To: jeremy.lansman@gmail.com Cc: linux-wireless Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Fri, Oct 24, 2014 at 10:05 PM, jeremy lansman wrote: > Hi. > > I beg your pardon for asking a newbe question...but..here goes anyway. > > My problem is with an Intel Advanced 6230. I have noted over the year + I > have used it under Ubuntu that it seems to have a problem when I move the > laptop. This is consistent with a channel estimation (tap equalizer) issue > under COFDM modulation. > No, I do not know about wi-fi, and I do not relish digging into driver > stuff. But I do know digital RF in general. > If it is going to take more hoursout of my life , maybe I should buy an > external wi-fi for the lap top and put up with the resultant klutz. Please try this: https://git.kernel.org/cgit/linux/kernel/git/iwlwifi/iwlwifi-fixes.git/commit/?id=a0855054e59b0c5b2b00237fdb5147f7bcc18efb It is on its way upstream. > > This is ping to my AP after I move about: > 64 bytes from 10.5.50.1: icmp_seq=509 ttl=64 time=1057 ms > 64 bytes from 10.5.50.1: icmp_seq=510 ttl=64 time=5382 ms > 64 bytes from 10.5.50.1: icmp_seq=511 ttl=64 time=4386 ms > 64 bytes from 10.5.50.1: icmp_seq=512 ttl=64 time=3383 ms > 64 bytes from 10.5.50.1: icmp_seq=513 ttl=64 time=2376 ms > 64 bytes from 10.5.50.1: icmp_seq=514 ttl=64 time=1438 ms > 64 bytes from 10.5.50.1: icmp_seq=515 ttl=64 time=433 ms > 64 bytes from 10.5.50.1: icmp_seq=516 ttl=64 time=823 ms > 64 bytes from 10.5.50.1: icmp_seq=517 ttl=64 time=1533 ms > > > This is if I sit still a while: > 64 bytes from 10.5.50.1: icmp_seq=583 ttl=64 time=1.18 ms > 64 bytes from 10.5.50.1: icmp_seq=584 ttl=64 time=1.79 ms > 64 bytes from 10.5.50.1: icmp_seq=585 ttl=64 time=0.871 ms > 64 bytes from 10.5.50.1: icmp_seq=586 ttl=64 time=2.96 ms > 64 bytes from 10.5.50.1: icmp_seq=587 ttl=64 time=1.28 ms > 64 bytes from 10.5.50.1: icmp_seq=588 ttl=64 time=1.57 ms > 64 bytes from 10.5.50.1: icmp_seq=589 ttl=64 time=1.03 ms > > WIFI worked after I installed Unbuntu Trusty, but an update seems to have > broken it, sending performance back to what it was under 12.04. > > So.. do you think it might be a simple fix related to channel estimation? > > Thank you. > > > > > > > -- > Jeremy Lansman > New York City USA, +1 347 696 0120 > Western Cape RSA, +27 21 300 2105 > Anchorage AK USA,+1 907 339 3800 > Skype Lansmankyes > Fax 27862460713 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-wireless" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html