From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Barber Subject: Re: MCS field - STBC and Ness Date: Thu, 01 Nov 2012 17:24:59 -0700 Message-ID: <509312DB.7070100@superduper.net> References: <4FAC5DE0.90708@superduper.net> <4FACBA13.9040509@neratec.com> <4FAD41E4.3090803@superduper.net> <4FAD43F0.20807@superduper.net> <1336761346.8739.3.camel@jlt3.sipsolutions.net> <4FADE69F.9040100@superduper.net> <1341479550.4455.36.camel@jlt3.sipsolutions.net> <5091C0BC.4040305@superduper.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5091C0BC.4040305-vp0mx6+5gkqFX2APIN6yfw@public.gmane.org> Sender: radiotap-owner-sUITvd46vNxg9hUCZPvPmw@public.gmane.org To: Johannes Berg Cc: Wojciech Dubowik , radiotap-sUITvd46vNxg9hUCZPvPmw@public.gmane.org List-Id: radiotap@radiotap.org OK - I have now posted 3 patches on the proposal page (see Attachments): 1. A patch that applies to the Linux kernel v3.7-rc1 to collect the new STBC and Ness parameters from a wireless driver, and add them into the MCS radiotap field. 2. A patch to the Intel wireless driver in the kernel to collect STBC and Ness information. 3. A patch to wireshark to display STBC and Ness information. With this I believe we have everything needed to start the 3 week comment period. Simon On 10/31/2012 05:22 PM, Simon Barber wrote: > Hi Johannes & Wojciech, > > My work has been on hold, but has recently come off hold. I'm getting > the patches together. As I rebase my work onto the current wireshark > trunk I've found a simpler implementation of STBC has been applied by > Wojciech. My proposal extends the STBC from his implemented 1 bit to the > full 2 bits allowed in the 11n specification, and also includes 2 bits > of Ness. I've posted an ieee80211 patch, and an intel driver patch (both > attached to the proposed radiotap extension page). l'll post a wireshark > patch shortly to start the comment period. > > Simon > > > On Thu 05 Jul 2012 02:12:30 AM PDT, Johannes Berg wrote: >> On Fri, 2012-05-11 at 21:27 -0700, Simon Barber wrote: >>> Another slight tweak - I think STBC is more commonly used than Ness (as >>> witnessed by Wojciech's interest), so give STBC the simpler encoding. I >>> believe Ness is used for beamforming soundings. >>> >>> Spec would look like this: >>> >>> known definition >>> 0x01 bandwidth >>> 0x02 MCS index known (in mcs part of the field) >>> 0x04 guard interval >>> 0x08 HT format >>> 0x10 FEC type >>> 0x20 STBC >>> 0x40 Ness - Number of extension spatial streams is known >>> 0x80 Ness2 - bit 1 (MSB) of Number of extension spatial streams. >>> >>> The flags field is any combination of the following: >>> >>> flag definition >>> 0x03 bandwidth - 0: 20, 1: 40, 2: 20L, 3: 20U >>> 0x04 guard interval - 0: long GI, 1: short GI >>> 0x08 HT format - 0: mixed, 1: greenfield >>> 0x10 FEC type - 0: BCC, 1: LDPC >>> 0x60 STBC - 0, 1 or 2: number of STBC streams >>> 0x80 Ness - bit 0 (LSB) of Number of extension spatial streams. >>> >>> What should I do to advance this as an approved radiotap extension? >> >> I suppose you already have patches for wireshark for this? I can help >> you out with a patch for the Linux kernel as an example producer of >> this, and then I think just repost it to the list again to leave some >> more discussion time. >> >> johannes >>