Return-path: Received: from ey-out-2122.google.com ([74.125.78.25]:55869 "EHLO ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754258AbYLFLNA (ORCPT ); Sat, 6 Dec 2008 06:13:00 -0500 Received: by ey-out-2122.google.com with SMTP id 6so160090eyi.37 for ; Sat, 06 Dec 2008 03:12:58 -0800 (PST) From: Henning Rogge To: Johannes Berg Subject: Re: RFC Patch v2: Add signal strength to nl80211station info Date: Sat, 6 Dec 2008 12:12:50 +0100 Cc: "linux-wireless" References: <200811252131.30161.hrogge@googlemail.com> <200812060026.50636.hrogge@googlemail.com> <1228554920.15939.2.camel@johannes.berg> In-Reply-To: <1228554920.15939.2.camel@johannes.berg> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart122860125.EtH9Ki5sAP"; protocol="application/pgp-signature"; micalg=pgp-sha1 Message-Id: <200812061212.55491.hrogge@googlemail.com> (sfid-20081206_121313_522809_2C5882DF) Sender: linux-wireless-owner@vger.kernel.org List-ID: --nextPart122860125.EtH9Ki5sAP Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Saturday 06 December 2008 10:15:20 Johannes Berg wrote: > Yes, well, depending on which values you used you might have run into > the fact that the values from the tables were already rounded. Both errors happen for 20 Mhz channels... one of them is definitely a typo= in=20 the wiki. I get 144.4 MBit/s (wiki says 144.0) for MCS 15 (long GI) and 115.6 MBit/s (wiki says 173.3, which is a typo !) for MCS 27(short GI). in pseudocode: =2D---------------- int modulation =3D mcs & 7; int streams =3D mcs / 8; int bitrate =3D (flags & 40MHZ) ? 13500000 : 6500000; if (modulation < 4) bitrate *=3D (modulation + 1); else if (modulation =3D=3D 4) bitrate *=3D (modulation + 2); else bitrate *=3D (modulation + 3); bitrate *=3D streams; if (flags & SHORT_GI) bitrate =3D (bitrate * 10) / 9; return (bitrate + 50000) / 100000; // do NOT just round down Henning --nextPart122860125.EtH9Ki5sAP Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) iEYEABECAAYFAkk6XjcACgkQcenvcwAcHWczQwCgiwMouQqpfni5bbTxcN49G3SI HsgAn0VOiLObtbqtdW4LNl9EcCfzEHlT =Baak -----END PGP SIGNATURE----- --nextPart122860125.EtH9Ki5sAP--