From owner-freebsd-wireless@FreeBSD.ORG Wed Oct 29 09:33:37 2014 Return-Path: Delivered-To: freebsd-wireless@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 768F2B38 for ; Wed, 29 Oct 2014 09:33:37 +0000 (UTC) Received: from mail-yh0-x229.google.com (mail-yh0-x229.google.com [IPv6:2607:f8b0:4002:c01::229]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 33CF5C20 for ; Wed, 29 Oct 2014 09:33:37 +0000 (UTC) Received: by mail-yh0-f41.google.com with SMTP id b6so368136yha.28 for ; Wed, 29 Oct 2014 02:33:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type; bh=rfJup4ehF93mmO7F5Z99A6hDTE3Y+JL2aqaGnzq1wkY=; b=lblPI2xhSMaxoU9sNtkD5WdB3tf9uDS2HzWSVUpyKF1iwWdGWCJF+sbzluY/UzR1Or 7Yjp/Vp9JasATN0wilwWmf+c/H+WRyf30TIjZ8BWVx9wwQ6YNi4fxMVZkoiq28tE2COn u+KhGRUOIEwlvAzt0eNPYjqxN2WGgVsOrq7yQ63UcTWS38GNts+w5BbF7aap64mP2Fe6 ENYBP2u27fOyGQ3CQSYkBOSVxCIXVM6gBWalcSs6PADf0S5u4DzZC8M/qhsTPLd/UlVY V33IO0CWy+FdQicdOcTmGQAvPUtOKBQ8gKRYsUhIMoBCji7DRpDgRKmF+Jy0q2ATNWrO d38w== X-Received: by 10.236.62.136 with SMTP id y8mr835997yhc.124.1414575216459; Wed, 29 Oct 2014 02:33:36 -0700 (PDT) MIME-Version: 1.0 Received: by 10.170.153.196 with HTTP; Wed, 29 Oct 2014 02:33:16 -0700 (PDT) In-Reply-To: <1E0B1592-5212-4D65-8F08-344EC215EA47@student.ethz.ch> References: <1E0B1592-5212-4D65-8F08-344EC215EA47@student.ethz.ch> From: Sergey Ryazanov Date: Wed, 29 Oct 2014 13:33:16 +0400 Message-ID: Subject: Re: Time-of-flight positioning - Atheros To: Graf Monika Content-Type: text/plain; charset=ISO-8859-1 Cc: "freebsd-wireless@freebsd.org" X-BeenThere: freebsd-wireless@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "Discussions of 802.11 stack, tools device driver development." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Oct 2014 09:33:37 -0000 Hi Monika, 2014-10-29 11:44 GMT+03:00 Graf Monika : > Hello Everyone > > I am currently at a project where I am using Atheros Chipsets AR9590 with the ath9k driver. > It's a bit strange to ask questions about linux driver in freebsd-wireless mailing list. Just in case, there are two mailing lists for ath9k: ath9k-devel and linux-wireless. > I am wondering how the time-of-flight information can be retrieved per packet in most recent Atheros chipsets. Is it required a proprietary HAL version ? > If you need a round-trip-time: take a tx timestamp from tx-complete descriptor of data frame, then take a timestamp from received ACK frame and then compute the time. To get received ACK frames from NIC you should enable control frames receiving in Rx filter. If you need more details about descriptor format or time of timestamp capture, then may be Adrian could help. BTW, a month ago or so, Lorenzo Bianconi added a dynamic ACK timeout estimation to the ath9k, based exactly on round-trip-time computation. -- BR, Sergey