From owner-freebsd-mobile Wed Dec 6 1:10: 8 2000 From owner-freebsd-mobile@FreeBSD.ORG Wed Dec 6 01:10:05 2000 Return-Path: Delivered-To: freebsd-mobile@freebsd.org Received: from mta01-svc.ntlworld.com (mta01-svc.ntlworld.com [62.253.162.41]) by hub.freebsd.org (Postfix) with ESMTP id A153837B400 for ; Wed, 6 Dec 2000 01:10:04 -0800 (PST) Received: from dmlb.org ([62.253.135.85]) by mta01-svc.ntlworld.com (InterMail vM.4.01.02.27 201-229-119-110) with ESMTP id <20001206091003.HESS15992.mta01-svc.ntlworld.com@dmlb.org>; Wed, 6 Dec 2000 09:10:03 +0000 Received: from dmlb by dmlb.org with local (Exim 3.03 #1) id 143aag-0001C4-00; Wed, 06 Dec 2000 09:10:18 +0000 Content-Length: 3223 Message-ID: X-Mailer: XFMail 1.3 [p0] on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <200012060604.XAA76044@harmony.village.org> Date: Wed, 06 Dec 2000 09:10:18 -0000 (GMT) From: Duncan Barclay To: Warner Losh Subject: Re: ray committed Cc: mobile@FreeBSD.ORG, Wesley Morgan , Greg Lehey , Christopher Yeoh Sender: owner-freebsd-mobile@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Hi On 06-Dec-00 Warner Losh wrote: > In message <14893.53324.616401.949125@rockhopper.linuxcare.com.au> > Christopher Yeoh writes: >: As far as range goes, for our situation the aviators worked better >: than even wavelans with small antennas (yes this surprised us!). The >: situation is fairly unusual though. We're on different floors and the >: floor is made of reinforced concrete). Definitely no signal through >: the floor (eg being directly above doesn't work). However, the way the >: appartments are arranged there appears to be a path through a couple >: of appartments, outside and then into his side window, that the >: aviators can get a decent signal along. > > OK. I have two floors of my house. It is mostly wood based with the > usual duct work and such. I was down stairs and the "base" was > upstairs. I'd notice that sometimes things would just work, but that > heavy load doesn't work too well (eg a simple FTP or scp would swamp > the link). With the ZoomAir + Orinoco card (both with their default > tiny anntennas) I can still get good interactive performance and 1.5mbps > of ftp transfers. 1.5Mb/s data or about 160kB/s is about the theoretical limit for 802.11 at 2Mb/s and TCP/IP. I get 160kB/s ftp with my Libretto 50 over the raylink driver. > I see only slightly worse interactive performance > during the ftp than when it isn't running. With the aviator, the ftp > would just about shut down the link. Then after a while things would > get worse and worse. I could then take the laptop with the aviator > upstairs to 1' of the base station (which is just an intel box with an > aviator card) and get 0 throughput (which sounds like a driver > problem). The really strange part is that I can reboot both machines > and still get horrible to zero throughput. This points to "enemy > action" of some sort. > > I also have a wireless link with the older pre802.11 wavelan cards at > 2.4GHz to a friends house. Maybe that is impacting things. This could be a problem. Do you know if these are frequency hopping or direct sequence? If frequency hopping they are likely to be interfering. > It > doesn't impact the 802.11b cards that I use. We've also noticed > mysterious outages with the radio link for reasons that we still don't > understand. We've theorized that it may be due to other users in the > 2.4GHz band, which is also causing problems for the aviators. How long is the link? 802.11 was designed for a couple of 100m - this is not just Tx power/Rx sensitivity but stuff like resiliance to fading channels resiliance to mutli-path timing parameters (remember 150m/microsecond) ... > Or that > could just be a red herring. > > I have also tried turning off the wireless link above and things > didn't get better. It might be direct sequence then if it's WaveLAN. This wouldn't affect the Aviators. I think you might have a half dead card. > Warner Duncan --- ________________________________________________________________________ Duncan Barclay | God smiles upon the little children, dmlb@dmlb.org | the alcoholics, and the permanently stoned. ________________________________________________________________________ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-mobile" in the body of the message