From owner-freebsd-wireless@FreeBSD.ORG Wed Dec 4 03:30:15 2013 Return-Path: Delivered-To: freebsd-wireless@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 75758D32 for ; Wed, 4 Dec 2013 03:30:15 +0000 (UTC) Received: from mail-qe0-x22d.google.com (mail-qe0-x22d.google.com [IPv6:2607:f8b0:400d:c02::22d]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 302F81CA7 for ; Wed, 4 Dec 2013 03:30:15 +0000 (UTC) Received: by mail-qe0-f45.google.com with SMTP id 6so15728265qea.32 for ; Tue, 03 Dec 2013 19:30:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type:content-transfer-encoding; bh=3MRGQCh4qNRjYZKjU4p+QLGTOSkfGsOGuXJc9LnG8eM=; b=K8J+JYGMudTgpKLefKnPQySQ0gFrQKQZHFNoUJ6aZVhBJzAOQA4TFI46JFZkw9tliL iUsYcAVJgKSyi3b2EWAAKWxBtZt8m02KcYhfVXLo8Wsz8q90SFHgX2Xfw81oWCth0z6L XIi6sQENvI1M6eiryfatIPK/LeAgxgtMUNbELzN6ULbcFhsn/pNx9I7+rKipvVqG3J3H tR/62RLQ7dMK/SrSHmtFR/Ydh2Hjwjc589Yk/DDmp71cb0N9qjoqpIExfx1jF96/oIc9 1A3jioCCRQixWVmqmCAqV+Qy85+RBicoL4rK2fdO6gq1d7nqol4y/7NJOKJw7fLCua25 L4Uw== MIME-Version: 1.0 X-Received: by 10.49.131.5 with SMTP id oi5mr90661642qeb.38.1386127814362; Tue, 03 Dec 2013 19:30:14 -0800 (PST) Sender: adrian.chadd@gmail.com Received: by 10.224.53.200 with HTTP; Tue, 3 Dec 2013 19:30:14 -0800 (PST) In-Reply-To: <46B1EFC5-1AA4-4E51-B199-D4CDACEEA0AC@netgate.com> References: <46B1EFC5-1AA4-4E51-B199-D4CDACEEA0AC@netgate.com> Date: Tue, 3 Dec 2013 19:30:14 -0800 X-Google-Sender-Auth: SrOqG5N6G-ImiZdqjRlLerYrj_Q Message-ID: Subject: Re: Channel interference scan and manual selection From: Adrian Chadd To: Jim Thompson Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Cc: "freebsd-wireless@freebsd.org" X-BeenThere: freebsd-wireless@freebsd.org X-Mailman-Version: 2.1.17 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, 04 Dec 2013 03:30:15 -0000 On 3 December 2013 19:03, Jim Thompson wrote: > > On Dec 3, 2013, at 7:56 PM, Adrian Chadd wrote: > >> Now, ideally it'd actually check the channel for interference and >> channel busy status, and use _that_ metric. > > Ideally, it would attempt to get co-channel with other APs on the same ch= annel. > > Especially in 2.4GHz (or any of the 5GHz bands). > > Because you would *much* rather share the air (via collision avoidance) t= han raise the noise floor for someone (everyone) else. > > And, given that everyone has a DC receiver these days, there are NO =93no= n-overlapping channels=94. Right. Hence, interference and channel busy. The Atheros NIC channel busy tells you % busy with signal in the air _AND_ % busy receiving frames. So you can get an idea of what's actually going on. The basics are in the Atheros HAL. We just need a nice way to wrap it up and hand off channel survey results to the net80211 layer so it can make these decisions. -adrian