From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stuffed Crust Subject: Re: wireless: recap of current issues (configuration) Date: Mon, 16 Jan 2006 14:50:08 -0500 Message-ID: <20060116195008.GB12748@shaftnet.org> References: <20060113212605.GD16166@tuxdriver.com> <20060113213011.GE16166@tuxdriver.com> <20060113221935.GJ16166@tuxdriver.com> <1137191522.2520.63.camel@localhost> <20060114011726.GA19950@shaftnet.org> <43C97605.9030907@pobox.com> <20060115152034.GA1722@shaftnet.org> <43CAA853.8020409@errno.com> <20060116172817.GB8596@shaftnet.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="i9LlY+UWpKt15+FH" Cc: Sam Leffler , Jeff Garzik , Johannes Berg , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: To: Samuel Ortiz Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org --i9LlY+UWpKt15+FH Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jan 16, 2006 at 09:07:52PM +0200, Samuel Ortiz wrote: > That is true, thin MACs usually don't filter beacons on the same channel. > But in some cases (mainly power saving), you really want to avoid > receiving useless beacons and having the host woken up for each of them. > You may even want to not receive all the useful ones (the ones coming from > the AP you're joined with) if your softmac allows that. BSSID filtering doesn't matter as far as 802.11 powersave is concerned -- the power savings come from disabling the RF/BBP components. In other words, you can't receive or transmit traffic. If you're respecting the AP's beacon interval/DTIM settings, you only=20 wake up every couple of beacon intervals and listen for a beacon. IF=20 there's traffic waiting for you, then you wake up your transmitter, send=20 out a PSPOLL (or NULL/PSEnd) frame, get your traffic, then go back to=20 sleep again. =20 You may hear another beacon when the STA is awake, you may not. BSSID=20 filtering has nothing to do with 802.11 power save, but rather is=20 intented to reduce the host load (interrupts, processing overhead) and=20 thus the host power consumption. > This kind of beacon filtering is a big power saver, which is one of the > most important requirement for some platforms (phones, PDA, etc...). You need to be clear if you're talking about 802.11 powersave, versus=20 "power savings stemming from reducing the load on the host system",=20 which is where BSSID filtering is beneficial. - Solomon --=20 Solomon Peachy ICQ: 1318344 Melbourne, FL =20 Quidquid latine dictum sit, altum viditur. --i9LlY+UWpKt15+FH Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) iD8DBQFDy/jwPuLgii2759ARAkAmAKDaWvdZBiYlCZTEldQDQMYeaDRztgCfZvbj fzqcNrsbY4DyI8IbwTZqauI= =APT6 -----END PGP SIGNATURE----- --i9LlY+UWpKt15+FH--